
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y)%2: print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n for i in range(n):\n    for y in range(n):\n        if y%2==i%2: print "X",\n        else: print ".",\n    print\n   \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2: print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x + y % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n                                \n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n                                \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n    for y in range(n):\n        print "X"\n        \n        print\n    \n    \n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y) % 2:\n                print ".",\n            else:\n                print "X",\n        print\n    \n    \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0:\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if y%2==x%2:\n                print "X",\n            else:\n                print ".",\n        print        \n            \n 
def sachovnice(n):\nfor i in range(n):\nfor j in range (n):\nif ((i + j) % 2 == 0):\nprint "X",\nelse:\nprint ".",\nprint\n 
def sachovnice(n):\n    for x in range(n):\n     for y in range(n):\n        if (y+x)%2==0:print "X",\n        else: print ".",\n     print\n   \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) % 2 == 0:\n        print "X",\n            else:\n                print ".", \n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n                \n    print\n 
def sachovnice(n):\n    for i in range (n):\n        if i % 2 == 1:\n            print (". " + "X ")*((n/2)-1)+ ". X"\n        else:\n            print ("X " + ". ")*((n/2)-1)+ "X ."\n    \n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y % 2 == 0):\n                if(i % 2 == 0):\n                    print "X",\n                else:\n                    print ".",\n            else 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print "
def sachovnice(n):\n    for y in range(n):\n        for w in range(n):\n            if((y+w)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n    \n   \n 
def sachovnice(n):\n    a = True\n    for z in range(n):\n      for y in range(n):\n                      \n        if a == True:\n         print "X",\n         a = False   \n        else:\n           print ".",\n           a = True \n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x % 2 == 1:\n                t = y - 1\n            else:\n                t = y\n            if t % 2 == 0:\n                print "X",\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if(x%2 == y%2):\n                print "X",\n            else:\n                print".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0:\n            p = 0\n        else:\n            p = 1\n        for j in range(n):\n            if j % 2 == p:\n                print "X",\n            else:\n 
def sachovnice(n):\n    for y in range(n):\n        if y % 2 == 0:\n        print "X",\n        else:\n            print ".",\n    print\n    for y in range(n):\n        if y % 2 == 0:\n        print ".",\n        else:\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            print "." if x%2 != y%2 else "X",\n        print\n    print\n 
def sachovnice(n):\n    for y in range(n):\n      for x in range(n):\n        if y+x%2==1:\n            print "X",\n        else:\n            print ".",\n\n\n      print\n 
def sachovnice(n):\n    for y in range(n):\n      for x in range(n):\n        if y+x%2==0:\n            print "X",\n        else:\n            print ".",\n\n\n      print\n 
def sachovnice(n):\n    for y in range(n):\n      for x in range(n):\n        if (y+x)%2==0:\n            print "X",\n        else:\n            print ".",\n\n\n      print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range (n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if ((x+y))%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n    \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        print\n        if (i%2 == 0):\n            for j in range(n):\n                if(j%2 == 0):\n                    print "X",\n                else:\n                    print ".",\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x%2==y%2):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n) :\n            if (x + y)%2 == 0 :\n                print "X",\n            else :\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1, n+1):\n        for j in range(1, n+1):\n            if ((i+j)%2): print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n/2):    \n        for i in range(n):\n            if i%2==0:\n                print "X",\n            else:\n                print ".", \n        print ""\n        for i in range(n):\n            i 
def sachovnice(n):\n    for i in range(n/2):    \n        for i in range(n):\n            if i%2==0:\n                print "X",\n            else:\n                print ".", \n        print ""\n        for i in range(n):\n            i 
def sachovnice(n):\n    for i in range(n/2):    \n        for i in range(n):\n            if i%2==0:\n                print "X",\n            else:\n                print ".", \n        print ""\n        for i in range(n):\n            i 
def sachovnice(n):\n    for i in range(n/2):    \n        for i in range(n):\n            if i%2==0:\n                print "X",\n            else:\n                print ".", \n        print ""\n        for i in range(n):\n            i 
def sachovnice(n):\n    for y in range(n):\n        if y%2==0:\n            for y in range(n):\n                if y%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if((i+j)%2):print".",\n            else:print"X",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y)%2==0: print "X",\n            else: print ".",    \n        print\n 
def sachovnice(n):\n   for y in range(n/2): \n    for y in range(n/2):\n        print "X .",\n    print\n    for y in range(n/2):\n        print ". X",\n    print 
def sachovnice(n):\n   line=0\n   \n   while line<n:\n    a=1    \n    for y in range(n):\n        if a%2: print "X",\n        else: print ".",\n        a+=1\n    print\n    line+=1\n    if line==n: break\n    a=0\n    for y in r 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if j in range(n):\n                if ((i+j) % 2 == 0):\n                    print "X",\n                else:\n                    print ".",\n 
def sachovnice(n=10):\n    for y in range(n):\n             for x in range(n):\n                   if (y+x)%2==1: print".",\n                   else: print"X",\n             print\n 
def sachovnice(n):\n    kriz = "X"\n    bodka = "."\n    for i in range (1,n+1):\n        if i%2 ==0:\n            for i in range (1,n/2):\n                if i%2==0:\n                    print bodka,\n                else:\n 
def sachovnice(n):\n    kriz = "X"\n    bodka = "."\n    for i in range (1,n+1):\n        if i%2 ==0:\n            for i in range (1,n/2):\n                if i%2==0:\n                    print bodka,\n                else:\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(0,n):\n        for j in range(0,n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else :\n                    print ".",\n            else :\n 
def sachovnice(n):\n    for i in range(n):\n        line=""\n        for j in range(n):\n            if i%2==0:\n                if j%2==0:\n                    line+="X"\n                else :\n                    line+="."\n 
def sachovnice(n):\n    for j in range(n):\n        for k in range(n):\n            if ((j+k)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 ==1: print ".",\n            else: print "X",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for j in range(n):\n           if ((y+j) % 2 == 0):\n                print "X",\n           else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range (n):\n        if i%2==0:\n            for y in range(n):\n                if y%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print \n 
def sachovnice(n):\n    p = n\n    a = "X"\n    while p > 0:\n        for y in range(n):\n            print a,\n            if a == "X": a = "."\n            else: a = "X"\n        p = p - 1\n        if p == 0: return\n        print\n 
def sachovnice(n):\n    p = n\n    a = "X"\n    while p > 0:\n        for y in range(n):\n            print a,\n            if a == "X": a = "."\n            else: a = "X"\n        p = p - 1\n        if p == 0: return\n        print\n 
def sachovnice(n):\n    p = n\n    a = "."\n    while p > 0:\n        for y in range(n):\n            \n            if a == "X": a = "."\n            else: a = "X"\n            print a,\n        p = p - 1\n        if p == 0: return\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0:\n            for i in range(1,n+1):\n                if i % 2 == 0:\n                    print ".",\n                else:\n                    print "X",\n        else: 
def sachovnice(n):\n    if (n==1):\n        print "X"\n    else:\n        for i in range (1,n+1):\n            print\n            if (i%2==0):\n                for i in range(1,n+1):\n                    if (i%2 ==0):\n 
def sachovnice(n):\n    for i in range \n    for y in range(n):\n        print "X",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n    for i in range \n    for y in range(n):\n        print "X",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n     if n%2:\n         for i in range (n//2):\n            print (n//2-1)*"X . "+"X . "+"X"\n            print (n//2-1)*". X "+". X "+"."\n         print (n//2-1)*"X . "+"X . "+"X"\n     else: \n         for 
def sachovnice(n):\n    for y in range(n):\n        for j in range(n):\n            if y%2 == 0 and j%2==0 or y%2==1 and j%2==1:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    s1=""\n    s2=""\n     
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2 ==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):    \n    for i in range(n):\n        if i%2 == 0:\n            for j in range(n):\n                if j%2 == 0:\n                    print "X",\n                else:\n                    print ".",\n        else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n    print 
def sachovnice(n):\n    for i in range(n):\n        for j in range (n):\n            if i%2==0 and j%2==0 or i==j and j==i: print "X",\n            elif i%2==1 and j%2==1: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n   \n 
def sachovnice(n):\n    for y in range(n):\n        for w in range(n):\n            if ((y + w) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*"X . "\n        else: print (n/2)*". X " 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%n==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            print (n/2)*("X"+" "+"."+" ")\n        else: print (n/2)*("."+" "+"X"+" ") 
def sachovnice(n):\n    a="X"\n    b="."\n    for j in range(n):\n        if j%2==0:\n            for i in range(n):\n                if i%2==0:\n                    print a,\n                else: print b,\n        else:\n            f 
def sachovnice(n):\n    a="X"\n    b="."\n    for j in range(n):\n        if j%2==0:\n            for i in range(n):\n                if i%2==0:\n                    print a,\n                else: print b,\n        else:\n            f 
def sachovnice(n):\n    a="X"\n    b="."\n    for j in range(n):\n        if j%2==0:\n            for i in range(n):\n                if i%2==0:\n                    print a,\n                else: print b,\n        else:\n            f 
def sachovnice(n):\n    a="X"\n    b="."\n    for j in range(n):\n        if j%2==0:\n            for i in range(n):\n                if i%2==0:\n                    print a,\n                else: print b,\n        else:\n            f 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for j in range(n):\n                if j%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print\n 
def sachovnice(n):\n    for x in range (n/2):\n        for y in range(n/2):\n            print "X" + " .",\n        print\n        for y in range(n/2):\n            print "." + " X",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        print\n        for y in range(n):\n            if (x%2==0 and y%2==0 or x%2!=0 and y%2!=0):\n                print "X",\n            else:\n                print".",\n        \n 
def sachovnice(n):\n    for y in range(n):\n        for X in range(n):\n            if (X + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if ((i+j)%2): print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if(y+2==i or y+4==i or y==i or y-2==i or y-4==i):\n                print "X",\n            else:\n                print".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if(y+2==i or y+4==i or y+6==i or y==i or y-2==i or y-4==i or y-6==i):\n                print "X",\n            else:\n                print".",\n 
def sachovnice(n):\n    x="X"\n    for y in range(n):\n        print\n        for i in range(n):\n            if x=="X":\n                print x,\n                x="."\n            else:\n                print x,\n                x="X 
def sachovnice(n):\n    x="X"\n    z="."\n    for y in range(n):\n        print\n        for i in range(n):\n            if n%2==0:\n                if y%2==0:\n                    if x=="X":\n                        print x,\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for j in range(n/2):\n                print "X",".",\n            print\n        else:\n            for j in range(n/2):\n                print ".","X",\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for j in range(n//2):\n                print "X",".",\n            if n%2==1: print "X",\n            print\n        else:\n            for j in range(n//2):\n 
def sachovnice(n):\n    for i in range(n):\n        f= ""\n        for y in range(n):\n            if (i+y)%2==0:\n                f+= ". "\n            else:\n                f+= "X "\n                print f\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y+i)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n   for x in range(n):\n        for y in range(n):\n            if ((x+y) % 2):\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        if x % 2 == 0: \n            sloup = ("X . "*(n+1))\n            print sloup[:(n*2)].strip()\n        else:\n            sloup = (". X "*(n+1))\n            print sloup[:(n*2)].strip( 
def sachovnice(n):\n    for y in range(1,n+1):\n        for j in range(1,n+1):\n            if ((y+j)%2):print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    kontrolaSachovnice=False\n    for i in range(n):\n        for j in range(n):\n            if kontrolaSachovnice==False:\n                print "X",\n                kontrolaSachovnice=True\n            else:\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if ((i+j)%2):\n                print ".",\n            else:\n                print "X",\n        print 
def sachovnice(n):\n    for a in range(n):\n        for b in range (n):\n            if ((a+b)%2==0): print "X",\n            else: print ".",\n        print\n    \n    \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y%2==0 and x%2==0) or (y%2==1 and x%2==1): print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if ((i+j)%2):\n               print ".",\n            else: \n                print "X",\n        print\n 
def sachovnice(n):\n    for a in range(1,n+1):\n        for b in range(1,n+1):\n            if (a%2!=1 and b%2!=1) or (a%2!=0 and b%2!=0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n/2):\n            print "X", "."\n        for y in range(n/2):\n            print ".", "X"\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n/2):\n            print "X", ".",\n        for y in range(n/2):\n            print ".", "X",\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n/2):\n            print "X", ".",\n        for y in range(n/2):\n            print ".", "X",\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n/2):\n            print "X", ".",\n        print\n        for y in range(n/2):\n            print ".", "X",\n        print\n 
def sachovnice(n):\n    for i in range(n**n):\n        print "X", ".",\n        print\n        for y in range(n/2):\n            print ".", "X",\n        print\n 
def sachovnice(n):\n    chars=["X","."]\n    c=0\n    for j in range(n):\n        for i in range(n):\n            print chars[c],\n            c+=1\n            c%=2\n        print 
def sachovnice(n):\n    chars=["X","."]\n    c=0\n    for j in range(n):\n        for i in range(n):\n            print chars[c],\n            c+=1\n            c%=2\n        print 
def sachovnice(n):\n    chars=["X","."]\n    c=0\n    for j in range(n):\n        for i in range(n):\n            print chars[c],\n            c+=1\n            c%=2\n        print\n        c = (j+1) % 2 
def sachovnice(n):\n    radek = 0\n    pismeno = 0\n    for i in range(n):\n        for j in range(n):\n            if (radek == 0):\n                if (pismeno == 0):\n                    print "X",\n                    pismeno = 1\n 
def sachovnice(n):\n    radek = 0\n    pismeno = 0\n    for i in range(n):\n        for j in range(n):\n            if (radek == 0):\n                if (pismeno == 0):\n                    print "X",\n                    pismeno = 1\n 
def sachovnice(n):\n    for z in range(n):\n        for y in range(n):\n            if (z % 2 == 0 and y % 2 == 0) or (z % 2 == 1 and y % 2 == 1) :\n                print "X",\n            else:\n                print ".",\n        print\ 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x +y) % 2 == 0: print "X",\n            else: print ".",\n        print 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if y%2 == 0 and x%2 == 0:\n                print "X",\n            elif y%2 == 1 and x%2 == 1:\n                print "X",\n            else:\n 
def sachovnice(n):\n    for y in range(1,n+1):\n        for i in range(1,n+1):\n            if (y+i)%2==1 :print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n            if y%2==0:\n                if z%2==0:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n  for i in range (n):\n    for j in range (n):\n        if (i+j) % 2 == 0:\n            print "X",\n        else:\n            print ".",\n    print\n 
def sachovnice(n):\n    for z in range(n//2):\n        for y in range(n//2):\n            print "X .",\n        print "X"\n        for y in range(n//2):\n            print ". X",\n        print "."\n    if n%2 != 0:\n        for v in ran 
def sachovnice(n):\n    for z in range(n//2):\n        for y in range(n//2):\n            print "X .",\n        if n%2 != 0:print "X"\n        else:print\n        for y in range(n//2):\n            print ". X",\n        if n%2 != 0:print 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i % 2)\n        \ndef radek(n,parita):\n    for j in range(n):\n        if (j % 2 == parita): print "X",\n        else: print ".",\n    print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if((y+x) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==1:\n                print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    stav = 0\n    pocatek = 0\n    if n%2 == 0:\n        pocatek = 1\n    for y in range(n+1):\n        for z in range(n+1):\n            if stav == 0:\n                print "X",\n                stav = 1\n 
def sachovnice(n):\n    stav = 0\n    pocatek = 0\n    if n%2 == 0:\n        pocatek = 1\n    for y in range(n):\n        for z in range(n):\n            if stav == 0:\n                print "X",\n                stav = 1\n            e 
def sachovnice(n):\n    for i in range(n):\n        print\n        for j in range(n):\n            if ((i+j)%2==0):\n                print "X",\n            else:\n                print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2==0:\n                print "x",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2==0:\n                print "x",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    zn = "X"\n    for x in range(n):\n        for y in range(n):\n            print zn,\n            if zn == "X":\n                zn = "."\n            else:\n                zn = "X"\n           \n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        if i%2 == 1:\n            for f in range(n):\n                if f%2 ==0:\n                    print "X",\n                else:\n                    if f == n-1:\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        if i%2 == 1:\n            for f in range(n):\n                if f%2 ==0:\n                    if f == n-1:\n                        print "X"\n                    else:\n 
def sachovnice(n):\n    for i in range(n):\n       for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n         \n        \n       print\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0:\n            for y in range(n):\n                if y % 2==0:\n                    print "X",\n                else:\n                    print ".",\n            print\n 
def sachovnice(n):\n    x=""\n    for i in range(n):\n        x=""\n        if i%2 == 0:\n            if n%2 == 1:\n                x="X"\n            print (n/2*"X . "),x\n        else:\n            if n%2 ==1:\n                x="."\ 
def sachovnice(n):\n    x=""\n    for i in range(n):\n        x=""\n        if i%2 == 0:\n            if n%2 == 1:\n                x="X"\n            print (n/2*"X . "),x\n        else:\n            if n%2 ==1:\n                x="."\ 
def sachovnice(n):\n    x=""\n    for i in range(n):\n        x=""\n        if i%2 == 0:\n            if n%2 == 1:\n                x="X"\n            print (n/2*"X . "),x\n        else:\n            if n%2 ==1:\n                x="."\ 
def sachovnice(n):\n    x=""\n    for i in range(n):\n        x=""\n        if i%2 == 0:\n            if n%2 == 1:\n                x="X"\n            print (n/2*"X . "),x\n        else:\n            if n%2 ==1:\n                x="."\ 
def sachovnice(n):\n    for i in range (n):\n        if i%2 == 0:\n            retazec = list(n*("X","."))\n        else:\n            retazec = list(n*(".","X"))\n            \n        for stlpec in range(n):\n            print retazec[( 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==1:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n          \n      \n 
def sachovnice(n):\n    lichy=1\n    for i in range(n):\n        for j in range(n):\n            if lichy == 1:\n                if(j % 2 == 0):\n                   print "X",\n                else: \n                   print ".",\n 
def sachovnice(n):\n    for y in range(n):  \n        if y % 2 == 0:\n            a="X"\n            b="."\n        else:\n            a="."\n            b="X"\n        for y in range(n):\n            if y % 2 == 0 :\n                pr 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+ (i % 2)) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(pocet):\n    for i in range(pocet):\n        for j in range(pocet):\n            if (j + (i % 2))%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print \n 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i % 2)\n        \ndef radek(n, parita):\n    for j in range(n):\n        if (j % 2 == parita): print "X",\n        else: print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (sloupec + (radek % 2 ))% 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):        \n        for j in range(n):\n            if (j+(i%2))%2 ==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(j+(i%2))%2==0:\n                print "X",\n            else:\n                print ".",\n        print    \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+(i%2))%2 ==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    radek = ""\n    radek2 = ""\n    for y in range(n):\n        radek = radek + "X."\n        radek2 = radek2 + ".X"\n    for x in range(n):\n        if x % 2 == 0:\n            print radek\n        else:\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y + x) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i % 2 == 0:\n                if j % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i % 2 ==0 and j % 2 ==0) or (i % 2 == 1 and j % 2 ==1):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    a = "X"\n    b = "."\n    for i in range(n):\n        for j in range(n/2):\n            if (i%2) == 0:\n                print a, b,\n            else:\n                print b, a,\n        print\n    print\n 
def sachovnice(n):\n    a = "X"\n    b = "."\n    for i in range(n):\n        for j in range(n):\n            if j%2 == 0:\n                print a\n    print\n 
def sachovnice(n):\n    a = "X"\n    b = "."\n    for i in range(n):\n        for j in range(n):\n            if j%2 == 0:\n                print a\n    print\n 
def sachovnice(n):\n    a = "X"\n    b = "."\n    for i in range(n):\n        for j in range(n):\n            if j%2 == 0:\n                print a\n                \n    print\n 
def sachovnice(n):\n    i = 1\n    a = 1\n    while i <= n:\n        i = i + 1\n        for b in range(n):\n            if a == 1:                \n                print "X",\n                a = 0\n            else:\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n/2):\n            print "X",\n            print ".",\n        print\n        for j in range(n/2):\n            print ".",\n            print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==1:\n            for y in range(n):\n                if y%2==0:\n                    print ".",\n                else:\n                    print "X",\n            print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y+i)%2 == 1:\n                print ".",\n            else:\n                print "X",\n        print 
def sachovnice(n):\n    if n%2==0:\n        for y in range(n/2):\n            print ((n/2)-1)*"X . "+"X ."\n            print ((n/2)-1)*". X "+". X"\n    else: \n        for y in range((n/2)-1):\n            print ((n/2)-1)*"X . "+"X 
def sachovnice(n):\n    for i in range(1, n+1):\n        if(i % 2 == 0):\n            print " ".join([". X" for x in range(n / 2)])\n        else:\n            print " ".join(["X ." for x in range(n / 2)])\n 
import math\n\ndef sachovnice(n):\n    flipper = 0\n    for i in range(n):\n        for j in range(n):\n            if(flipper % 2 == 0):\n                print "X",\n            else:\n                print ".",\n                \n 
def sachovnice(n):\n    switch = True;\n    for y in range(n):\n        for y in range(n):\n            if switch == True: \n                print "X",\n            else:\n                print ".",\n            switch = not switch\n 
def sachovnice(n):\n    switch = True;\n    for y in range(n):\n        for y in range(n):\n            if switch == True: \n                print "X",\n            else:\n                print ".",\n            switch = not switch\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n   for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n       \n 
def sachovnice(n):\n    a=0\n    for i in range(n): 
def sachovnice(n):\n    a=0\n    for i in range(n): 
def sachovnice(n):\n    a=0\n    for i in range(n):\n 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n) 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n) 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n)\n 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n) 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n) 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n): 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n): 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n):\n 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n):\n            if a%2==0: 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n):\n            if a%2==0: 
def sachovnice(n):\n    a=0\n    for i in range(n):\n        for j in range(n):\n            if a%2==0:\n 
def sachovnice(n):\n    a=1\n    for i in range(n):\n        for j in range(n):\n            if a%2==0:\n                print ".",\n            else:\n                print "X",\n            a+=1\n        print\n        if n%2==0:\n 
def sachovnice(n):\n    a="X"\n    b="."\n    p=""\n    for i in range (n):\n        for y in range (n):\n            print a,\n            p=a\n            a=b\n            b=p\n        p=a\n        a=b\n        b=p\n        print\ 
def sachovnice(n):\n    a="X"\n    b="."\n    p=""\n    for i in range (n):\n        for y in range (n):\n            print a,\n            p=a\n            a=b\n            b=p\n        if n % 2 == 0:\n            p=a\n            a= 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (sloupec+radek)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if(i+y)%2==0:\n                print"X",\n            else: print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        radek (n,i%2)\ndef radek(n,parita):\n    for j in range(n):\n        if j%2==parita: print "X",\n        else: print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0: print (n//2)*"X . " + "X"\n        else: print (n//2)*". X " + "."\n 
def sachovnice(n):\n    a = 0\n    for y in range(n):\n        for i in range(n):\n            if a == 0:\n                print "X",\n                a = 1\n            else:\n                print ".",\n                a = 0\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        if(i%2==0):\n            print(((n/2)-1)*"X . "+"X")\n        else:\n            print(((n/2)-1)*". X "+".")\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0:\n            print ((n/2)-1)*(("X . "))+("X .")\n        else:\n            print ((n/2)-1)*((". X "))+(". X")\n 
def sachovnice(n):\n    for i in range(n):\n        \n        for j in range(n):\n            \n            if (i%2 == 0 and j%2 != 0) or (i%2 !=0 and j%2==0):\n                print ".",\n            else:\n                print "X",\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if i%2==1:\n                if j%2==1:\n                    print "X",\n                else:\n                    print ".",\n            els 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n            if ((y % 2) + z)% 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    if n%2==0:\n        for i in range(n/2):\n            for y in range(n/2):\n                print "X .",\n            print ""   \n            for j in range(n/2):\n                print ". X",\n            print " 
def sachovnice(n):\n    if n%2==0:\n        for i in range(n/2):\n            for y in range(n/2):\n                print "X .",\n            print    \n            for j in range(n/2):\n                print ". X",\n            print \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print("X"),\n            else:\n                print("."),\n        print\n 
def sachovnice(n):\n   for s in range (n):\n    if s%2==0:\n        for y in range(n):\n            if y%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n    else:\n        for y in range( 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x % 2==0 and y % 2 == 0: print "X",\n            elif x % 2 == 1 and y % 2 == 0: print ".",\n            elif x % 2 == 0 and y % 2 == 1: print ".",\n 
def sachovnice(n):\n    a = 0\n    while (a != n):\n        \n        for i in range(n):\n            if (i % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        a+=1\n        if (a == n):\n 
def sachovnice(n):\n    a = "X"\n    b = "."\n    for i in range(1, n + 1):\n        if i % 2 == 0:\n            for j in range (1, n + 1):\n                if j % 2 == 0:\n                    print a,\n                else:\n 
def sachovnice(n):\n    for i in range(n):\n        \n        for y in range(n):\n            if i%2 and y%2 or not i%2 and not y%2:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==1: print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 1:\n                print ".",\n            else: print "X",\n        print 
def sachovnice(n):\n    for x in range(n):\n        for y in range (n):\n            if ((x % 2 == 0 and y % 2 == 0) or (x % 2 == 1 and y % 2 == 1)):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if ((x%2==0) and (y%2==0)) or ((x%2==1) and (y%2==1)) : print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    bubok = True\n    for _ in range(n):\n        for y in range(n):\n            if bubok:\n                print "X",\n                t = False\n            if not bubok:\n                print ".",\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n//2):\n            if y%2 == 0:\n                print "X .",\n            else:\n                print ". X",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        if y%2 == 0:\n            for x in range(n):\n                if x%2==0:\n                    print "X",\n                else:\n                    print ".",\n        else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) %2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2 == 0):\n                print "X",\n            else: \n                print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2 == 0):\n                print "X",\n            else: \n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        \n        for x in range(n):\n            if (y % 2 == 0 and x % 2 == 0) or (y % 2 == 1 and x % 2 == 1):\n                print "X",\n            else: print ".",\n        print 
def sachovnice(n):\n    for z in range(n):\n        for y in range(n):\n            if(z%2==0):\n                if(y%2==0):\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if ((x+y)%2) == 0:\n                print "X",\n            else: \n                print ".",      \n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2!=0:\n            for j in range(n):\n                if j%2==0:\n                    print ".",\n                else:\n                    print "X",   \n        else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==1:print ".",\n            else:print "X",\n        print 
def sachovnice(n):\n    j = 0\n    k = 1\n    if (k == 1):\n        for y in range(n):\n            if (y % 2 == 0):\n                j += 1\n                print "X",\n            if (y % 2 != 0):\n                    j += 1\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if(y%2==x%2):\n                print "X",\n            else:\n                print".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if(x%2==y%2):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (y+x) % 2 ==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(1,n+1):\n        if y%2==0:\n            for x in range(1,n+1):\n                if x%2==0:\n                    print "X",\n                else:\n                    print ".",\n        else:\ 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range (1,n+1):\n            if i%2==1 and j%2==1 or i%2==0 and j%2==0:\n               print"X",\n            else:\n               print".",\n        print\n      \n\ 
def sachovnice(n):\n    for i in range(n):\n    for j in range(n):\n        if ((i+j) % 2 == 0):    \n    print "X",\n        else:\n            print ".",\n            print\n    return\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 1:\n                print ".",\n            else: \n                print "X",\n        print\n 
def sachovnice(n):\n    a,b="X","."\n    for x in range(n):\n        for y in range(n):\n            if y%2==0:\n                print a,\n            else: \n                print b,\n        print\n        a,b=b,a\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 1:\n                print ".",\n            else: print "X",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==1:print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    p = 0\n     
def sachovnice(n):\n    p = 0\n     
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:print "X",\n            else: print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (y+x)%2==0:\n                print "X",\n            else:\n                print ".",\n            if x==3:\n                print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (y+x)%2==0:\n                print "X",\n            else:\n                print ".",\n            if x==n-1:\n                print\n 
def sachovnice(n):\n    for i in range(n):\n        for k in range(n):\n            if (i+k)%2==0:print"X",\n            else: print".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n           \n            \n    \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0: print "X",\n            else: print ".",\n        print\n\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i % 2 == 0:\n                if j % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y + x)%2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 1:print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for i in range (n): \n        for y in range(n):\n            if (i%2 == 0):\n                if (y%2 == 0):\n                    print "X",\n                else:\n                    print ".",\n            else: 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for t in range(1,n+1):\n            if ((i%2!=0) and (t%2==0))or((i%2==0) and (t%2!=0)):print ".",\n            else:print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i+j)%2==1:\n                print ".",\n            else: print "X",\n        print\n   \n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else: \n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        print\n        for y in range(n):\n            if ( (y % 2 != 0 and x % 2 == 0) or (y % 2 == 0 and x % 2 != 0)):\n                print ".",\n            else:\n                print "X", 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2 == 0 and j%2 == 0:\n                print "X",\n            elif i%2 <> 0 and j%2 <> 0:\n                print "X",\n            else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    x=False\n    for i in range(n):\n        if x==True:\n            x=False\n        else:\n            x=True\n        for j in range(n):\n            if x==True:\n                print "X",\n                x=Fal 
def sachovnice(n):\n    x=True\n    for i in range(n):\n        for j in range(n):\n            if x==True:\n                print "X",\n                x=False\n            else:\n                print ".",\n                x=True\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1, n+1) :\n            if i%2 == 1 :\n                if j%2 == 1 :\n                    print "X",\n                else :\n                    print ".",\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if (i+j)%2==1: print".",\n            else: print "X",\n        \n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==1: print ".",\n            else: print "X",         \n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==1:print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i+j)%2 == 0:\n                print "X",\n            if(j+i)%2 == 1:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range (n/2):\n        for y in range(n/2):\n            print 1*"X",\n            print 1*".",\n        print\n        for y in range(n/2):\n            print 1*".",\n            print 1*"X",\n        pri 
def sachovnice(n):\n    if n%2==0:\n        for i in range (n/2):\n            for y in range(n/2):\n                print "X",\n                print ".",\n            print\n            for y in range(n/2):\n                print ".",\ 
def sachovnice(n):\n    if n%2==0:\n        for i in range (n/2):\n            for y in range(n/2):\n                print "X",\n                print ".",\n            print\n            for y in range(n/2):\n                print ".",\ 
def sachovnice(n):\n    for i in range(n):\n        for j in range (n):\n            if i%2==0 and j%2==0 or i==j: print "X",\n            elif i%2==1 and j%2==1: print "X",\n            else: print ".",  \n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range (n):\n            if (i+j)%2==0:\n                print "X",\n            else: print ".",\n        print\nprint\n 
def sachovnice(n):\n    for y in range(n):\n        for j in range(n):\n            if (j+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y+i)%2==0: print "X",\n            else: print ".",\n        print 
def sachovnice(n):\n    c = 1\n    for j in range(1,n+1):\n        for i in range(1,n+1):\n            \n            if(i % 2 == c):\n                print "X",\n            else:\n                print ".",\n        print ""\n 
def sachovnice(n):\n    c = 1\n    for j in range(1,n+1):\n        tempstr = ""\n        for i in range(1,n+1):\n            \n            if(i % 2 == c):\n                tempstr += "X "\n            else:\n                tempstr 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n    \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n           if (x+y)%2 == 0:\n                print "X",\n           else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n            if y%2:\n                if z%2:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for y in range(0,n):\n        if y%2==0:\n           print "X","."\n        else:\n            print ".","X"\n        \n 
def sachovnice(n):\n    for y in range(0,n):\n        if y%2==0:\n           for i in range (0,n):\n               if i%2==0:\n                    if i<n-1:\n                       print "X",\n                    else:\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if ((x+y) %2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y) % 2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    \n    if n%2 == 0:\n        for a in range(n/2):\n            for b in range (n/2):\n                print "X",\n                print ".",\n            print\n            for c in range (n/2):\n                pr 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if ((j+i)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
 
def sachovnice(n):\n    for y in range(n):\n        for j in range(n):\n            if (y+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n            \n        \n    \n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if (y+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(j +(i%2))%2==0:\n                print "X",\n            else:\n                print ".",  \n        print\n 
def sachovnice(n):\n    for r in range(n):\n        for s in range(n):\n            if r % 2 == s % 2:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print       \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i%2==0 and j%2==0 and j!=n-1) or (i%2==1 and j%2==1 and j!=n-1):\n                print "X",\n            elif(i%2==0 and j%2==0 and j==n-1) or (i%2==1 an 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else:\n                    print ".",\n            if i%2==1:\n 
def sachovnice(n):\n    znak = True\n    for i in range(n):\n        for j in range(n):\n            if znak:\n                print "X",\n            else:\n                print ".",\n            znak = not znak\n        print\n\n 
def sachovnice(n):\n    a = ["X", "."]\n    index = 0\n    for i in range(n):\n        for j in range(n):\n            print a[index],\n            index = int(not index)\n        print\n        a = a[::-1]\n 
def sachovnice(n):\n    a = ["X", "."]\n    index = 0\n    for i in range(n):\n        for j in range(n):\n            print a[index],\n            index = int(not index)\n        print\n        if n%2 ==0:\n            a = a[::-1]\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2==0):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(pocet):\n    for i in range(pocet):\n        for j in range (pocet):\n            if (j + (i %2))%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print \n                    \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n         if i%2==0:\n                if j%2==0:\n                    print "X",\n                else:\n                    print ".",\n         else:\n 
def sachovnice(n):\n    for radek in range(1,n+1):\n        for sloupec in range(1,n+1):\n            if radek%2==0 and sloupec%2==0:\n                print "X",\n            elif radek%2==1 and sloupec%2==1:\n                print "X", 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i % 2)\n\ndef radek(n, sudost):\n    for j in range (n):\n        if (j % 2 == sudost):\n            print "X",\n        else: print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n       for j in range(n):\n            if (j % 2 == i % 2): print "X",\n            else: print ".",\n       print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i%2 == 0 and j%2 == 0) or (i%2 != 0 and j%2 != 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if i%2 == 0 and j%2 == 0:\n                print "X",\n            elif i%2 != 0 and j%2 == 0:\n                print ".",\n            elif i%2 == 0 and j 
def sachovnice (n):\n    for y in range (n):\n        if (y%2==0): \n            sudyRadek (n)\n        else: \n            lichyRadek (n)\n\ndef sudyRadek (n):\n    for i in range(n):\n        if (i%2==0):\n            print "X",\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n    \n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if (i+y)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range (n):\n            if j%2==0 and i%2==0 or j%2==1 and i%2==1:\n                print"X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0: print "X",\n            else: print ".",\n        print\n\n 
def sachovnice(n):\n    for i in range (1,n+1):\n        for j in range (1,n+1):\n            if (i%2 == 0):\n                if (j%2 == 0):\n                    print "X",\n                else:\n                    print ".",\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else: print ".",\n        print\n    \n        \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if y % 2 == 0:\n                if x % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if y % 2 == 0:\n                if x % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if y % 2 == 0:\n                if x % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        if y%2==0:\n            for i in range(n):\n                if i%2==0: print "X",\n                else: print ".",\n        if y%2==1:\n            for i in range(n):\n                i 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y+i)%2==0:print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for y in range(1,n+1):\n        for i in range(1,n+1):\n            if (i+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n               \n        print\n 
def sachovnice(n):\n    chars=["X","."]\n    chars.append(chars[0])\n    i=1\n    j=0\n    for x in range(n*n):\n        print chars[(x%2)+(j%2)],\n        if i==n:\n            i=0\n            j+=1\n            print\n        i%2 
def sachovnice(n):\n    chars=["X","."]\n    chars.append(chars[0])\n    for x in range(n):\n        for y in range(n):\n            print chars[(y%2)+(x%2)],\n        print\n\n 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if((i+j)%2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n    \n        \n    print\n 
def sachovnice(n):\n   for i in range(n):\n        for j in range (n):\n            if ((i+j)%2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 ==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if i%2 + y %2 == 1: print ".",\n            else: print "X",\n        print\n\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                print "X",\n            else:\n                print ".",\n        k += 1    \n        print""\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                if (x == n - 1):\n                    print "X"\n            else:\n                print ".",\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                if (x == n - 1):\n                    print "X"\n            else:\n                print ".",\n 
def sachovnice(n):\n    k = 0\n    for y in range(n):\n        for x in range(n):\n            if (x % 2 == k % 2):\n                if (x == n - 1):\n                    print "X"\n                else:\n                    print "X", 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i*n+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if y % 2 == 0:\n                if x % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else: print ".",\n        print        \n            \n     \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\nfor i in range(n):\nfor j in range(n):\nif ((i+j)%2 == 0):\nprint "X",\nelse:\nprint ".",\nprint 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j + (i % 2)) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n    \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i%2==1 and j%2==0) or (i%2==0 and j%2==1):\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (((x+y) % 2) == 0): \n                print "X",\n            else:\n                print ".",\n        print\n 
def sudy(n):\n    for j in range(n):\n        if (j%2==0):\n            print "X",\n        else:\n            print ".",\n    print\n    \n    \ndef lichy(n):\n    for j in range(n):\n        if (j%2==1):\n            print "X",\n 
def sachovnice(n):\n    for x in range(n/2):\n        for y in range(n/2):\n            print "X",\n            print ".",\n        print\n        for y in range(n/2):\n            print ".",\n            print "X",\n        print\n 
def sachovnice(n):\n    i = 1\n    for x in range(n):\n        for y in range(n):\n            if i == 1:\n                print "X",\n            else:\n                print ".",\n            i = i*(-1)\n        print\n 
def sachovnice(n):\n    i = -1\n    for x in range(n):\n        for y in range(n):\n            i = i*(-1)\n            if i == 1:\n                print "X",\n            else:\n                print ".",\n        i = i*(-1)\n        p 
def sachovnice(n):\n    i = -1\n    for x in range(n):\n        for y in range(n):\n            i = i*(-1)\n            if i == 1:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n   for radek in range (n):\n        for sloupec in range (n):\n            if (radek+sloupec)%2==0:\n                print "X",\n            else: \n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if ((x+y)%2==0):\n                print"X",\n            else:\n                print".",\n        print         \n    \n 
def sachovnice(n):\n    for y in range(n):\n        for j in range(n):\n            if ((y%2==0)and(j%2==0))or((y%2==1)and(j%2==1)):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2 == 0:\n            for j in range(n):\n                if j%2 == 0:\n                    print "X",\n                else:\n                    print ".",\n        else:\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        \n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if i%2==1:\n                if j%2==1:\n                    print "X",\n                else:\n                    print ".",\n            els 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:print".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n            \n        \n   \n        \n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if i%2==1:\n                if j%2==0: \n                    print ".",\n                else: \n                    print "X",\n            e 
def sachovnice(n):\n    h=0\n    for i in range(n):\n        for j in range(n):\n            h=h+1\n            if h%2==0:\n                print ".",\n            else:\n                print "X",\n        print\n        if n%2==0:\ 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n            if (z+(y % 2))%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for x in range(n):\n        print\n        for y in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for radek in range(n):\n        if n % 2 == 0:\n            if radek % 2 == 0:\n                print ("X "+". ")*((n//2)-1)+"X "+"."\n            else:\n                print (". "+"X ")*((n//2)-1)+". "+ 
def sachovnice(n):\n    for radek in range(n):\n        if n % 2 == 0:\n            if radek % 2 == 0:\n                print "X . " * ((n//2)-1) + "X ."\n            else:\n                print ". X " * ((n//2)-1) + ". X"\n        el 
def sachovnice(n):\n    for radek in range(n):\n        if n % 2 == 0:\n            if radek % 2 == 0:\n                print "X . " * ((n//2)-1) + "X ."\n            else:\n                print ". X " * ((n//2)-1) + ". X"\n        el 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x%2==y%2: print "X",\n            else: print ".",\n        print\n 
def print_row(chars, n):\n    for i in range(n):\n        if i % 2 == 0: print chars[0],\n        else: print chars[1],\n    print\n\ndef sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0:\n            print_row("X.", n)\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for h in range(0,n):\n                if h%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print ""\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for h in range(0,n):\n                if h%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print ""\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for h in range(0,n):\n                if h%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print \n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y+i) %2: print ".",\n            else: print "X",\n        print\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if (y+i) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n        \n                \n 
def sachovnice(n):\n    for i in range (n):\n        for j in range (n):\n            if ((i+j) % 2 ==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j % 2 == 0:\n                print ".",\n            else:\n                print "X"\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j+i % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j*i % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j*i % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j*i % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j*i % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if j % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,1+n):\n            if (j-1+i) % 2 == 0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):   \n    for j in range(n):\n        for k in range(n):\n            if ((j % 2 == 0 and k % 2 == 0) or (j % 2 != 0 and k % 2 != 0)):\n                print "X",\n            else:\n                print ".",\n        pri 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i==j or (i+j)%2==0 ):\n                print "X",\n            else:print ".",\n        print 
def sachovnice(n):\n    \n    for y in range(n):\n        for z in range(n):\n            if (y+z)%2==0:\n                print "X",\n            else: \n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n            if (y + z) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(1,n+1):\n        for x in range(1,n+1):\n            if (y + x) % 2 == 0: \n                print "X",\n            else:    \n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n):\n            if y%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n        for x in range(n):\n            if x %2 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n    print\n 
def sachovnice(n):\n    for riadok in range(n):\n        for i in range(n):\n            if (i+riadok)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i%2)==1 and (j%2)==0: print ".",\n            elif (i%2)==0 and (j%2)==1: print ".",\n            else: print "X",\n        print \n 
def sachovnice(n):\n    for j in range(n):\n        if j % 2 == 0:\n            for a in range(n):\n                if a % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n        else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i) % 2 == 0:                \n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if i % j == 0 and j%i ==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(2,n+2):\n        for j in range(1,n+1):\n            if (i%2)==(j%2):\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y + (x % 2))%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if i%2!=0:\n                if j%2==0:print ".",\n                else:print "X",\n            else:\n                if j%2==1:print ".",\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if y % 2 == 1:\n                x += 1\n            if x % 2 == 0: \n                print "X",\n            else: \n                print ".",\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==0 and j%2==0 or i%2>0 and j%2>0:\n                print "X",\n            else:\n                print ".",\n        print\n       \n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n       for j in range(n):\n            if j % 2 == 0 and i % 2 == 1:\n                print ".",\n            elif j % 2 == 0 and i % 2 == 0:\n                print "X",\n            elif j % 2 = 
def sachovnice(n):\n    \n    for y in range(n):\n        for i in range(n):\n            if y%2==0:\n                if i%2==0:print "X",\n                else: print ".",\n            else:\n                if i%2==0:print ".",\n 
def sachovnice(n):\n    for y in range(n):\n        radek(n,y%2)\n     \ndef radek(n,rovnost):\n    for z in range(n):\n        if(z%2==rovnost):print"X",\n        else:print".",\n    print\n        \n 
def sachovnice(n):    \n    for y in range(n):\n        a=y\n        for y in range(n):\n           a+=1\n           if a%2!=0:\n             print "X",\n           else:\n             print ".",\n        print\n   \n  \n 
def sachovnice(n):\n    for i in range(1, n+1):\n        for j in range(1, n+1):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i%2==j%2):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if j % 2 == i%2:\n                print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        if y%2 == 0: sudost = True\n        else: sudost = False\n        for i in range(n):\n            if sudost == True:\n                print "X",\n                sudost = False\n 
def sachovnice(n):\n    k=0\n    for y in range(n):\n        for i in range(n):\n            if y %2==1:                \n            if i %2 ==1 :\n        print "X",\n            else:\n        print ".",\n            else: 
def sachovnice(n):\n    for x in range (1,n+1):\n        for i in range (1,n+1):\n            if((x+i)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for a in range(n):\n            if (y+a)%2==0:\n                print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 ==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i %2)\ndef radek(n, parita):\n    for j in range(n):\n        if(j %2 == parita): print "X",\n        else: print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for o in range(n):\n            if (i+o) % 2:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for o in range(n):\n            if (i+o) % 2:\n                print ".",\n            else:\n                print "X",\n        print 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n                    \n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i%2 == 0):\n            if(j%2 == 0):\n                print "X",\n            else:\n               print ".",\n            else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):  \n                print "X",\n            else:\n                print ".",        \n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x%2 == 0 and y%2 == 0 or x%2==1 and y%2==1:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if x % 2 == y % 2:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range (n):\n        if i % 2 != 0:\n            if n % 2 == 0:\n                for y in range (n/2):\n                    print ".",\n                    print "X",\n            else:\n                for 
def sachovnice(n):\n    for i in range (n):\n        if i % 2 == 0:\n            if n % 2 == 0:\n                for y in range (int(n/2)):\n                    print "X",\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for rad in range(n):\n        for stlp in range(n):\n            if (rad+stlp)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==0 and j%2==0 or (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range (n):\n            if i%2==0:\n                if j%2==0:\n                    print "X",\n                else:\n                print ".",\n            else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i%2 == 0 and j%2 == 0) or (i%2 != 0 and j%2 != 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n            if (y+z)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (radek+sloupec)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j + (i % 2))% 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (radek + sloupec) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if y % 2 == 0:\n                if i % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(i,n+i):\n            if j%2==0:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if (i+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y%2==1 and x%2==0) or (y%2==0 and x%2==1):\n                print ".",\n            else:\n                print "X",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i % 2 == 0 and j % 2 == 0 or i % 2 != 0 and j % 2 != 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) % 2 == 0:\n                print "X",\n            else:\n            print ".",\n        print 
def sachovnice(n):\n    for y in range(n-1):\n        print "X .",\n    print\n    for y in range(n-1):\n        print ". X",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if ((x + y) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for z in range(n//2): \n        for y in range(n//2):\n            print "X .",\n        print"X"\n        for y in range(n//2):\n            print ". X",\n        print"."\n        for v in range(n//2):\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print  "X",\n                else: print "."\n        \n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print  "X",\n            else: print ".",\n        \n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n)\n            if (x + y) % 2 == 0: print X\n            else: print \n        print\n  \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n  \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x+y)%2==0:print "X",\n            else:print ".",\n        print\n   \n        \n   \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n): \n            if (x+y)%2==0:print "X",\n            else: print "." ,    \n        print\n 
def sachovnice(n):\n    for y in range(n):\n        print "X",\n    for x in range (n):\n        if (x + y) % 2 == 0: print "x"\n        else: print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for y in range (n):\n    for x in range (n):\n        if (x + y) % 2 == 0: print "x"\n        else: print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print "x",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print "x",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range (n):\n            if (x + y) % 2 == 0: print "x",\n            else: print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if (i % 2 == 0):\n            sudy_radek(n)\n        else:\n            lichy_radek(n)\n            \ndef sudy_radek(n):\n    for j in range(n):\n        if (j % 2 == 0):\n 
def sachovnice(n):\n    for i in range(n): \n        for j in range(n):\n                if j==i-4 or j==i-2 or j==i or j==i+2 or j==i+4:\n                print "x",\n                else:\n                    print ".",\n        prin 
def sachovnice(n):\n    for i in range(n): \n        for j in range(n):\n                if j==i-4 or j==i-2 or j==i or j==i+2 or j==i+4:\n                print "X",\n                else:\n                    print ".",\n        prin 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n    print\n 
def sachovnice(n):\n    for z in range(n//2):\n        for x in range(n//2):\n            print "X .",\n        print "X"\n        for y in range(n//2):\n            print ". X",\n        print "."\n    for x in range(n//2):\n        pri 
def sachovnice(n):\n    for z in range(n//2):\n        for x in range(n//2):\n            print "X .",\n        if n%2 != 0:print "X"\n        else:print\n        for y in range(n//2):\n            print ". X",\n        if n%2 != 0:print 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if ((i+y)%2==0):\n                print "X",\n            else:\n            print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n        if  i%2==0 and y%2==0 or y%2==1 and i%2==1:\n        print "X",\n        else:\n            print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n/2):\n        for y in range(n/2):\n            print "X .",\n        print\n        for y in range(n/2):\n            print ". X",\n        print\n 
def sachovnice(n):\n    if n%2 == 0:\n        for i in range(n/2):\n            for y in range(n/2):\n                print "X .",\n            print\n            for y in range(n/2):\n                print ". X",\n            print\n 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (radek + sloupec) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        print "X",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        print "X",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if ((y+i)% 2==0):       \n        print "X",\n            else:\n        print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for k in range(n):\n            if (i + k)%2 ==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i % 2)\ndef radek(n, parita):\n    for j in range(n):\n        if (j % 2 == parita): print "X",\n        else: print ".",\n    print 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i % 2)\ndef radek(n, parita):\n    for j in range(n):\n        if (j % 2 == parita): print "X",\n        else: print ".",\n    print 
def sachovnice(n):\n    for i in range (n//2): \n    riadky(n)\n    if n%2==1:\n        for d in range(n):\n            if d % 2 == 0:\n                print "X",\n            else:\n                print ".",    \n    \n        \nde 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==j%2: print "X",\n            else: print ".",\n        print        \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else: \n                print".",\n        print\n 
def sachovnice(n):\n    for j in range(n):\n        print\n        for i in range(n):\n            if i % 2 != 0 and j % 2 == 0:\n                print "X",\n                print ".",\n            elif i % 2 == 0 and j % 2 != 0:\n 
def sachovnice(n):\n    for j in range(n):\n        print\n        for i in range(n):\n            if i % 2 != 0 and j % 2 == 0:\n                print "X",\n                print ".",\n            elif i % 2 == 0 and j % 2 != 0:\n 
def sachovnice(n):\n    for j in range(n):\n        print\n        if j % 2 != 0:\n            for i in range(n):\n                if i % 2 == 0:\n                    print ".",\n                elif i % 2 != 0:\n                    print 
def sachovnice(n):\n    for y in range(n):\n        for z in range(n):\n        if (y+z)%2==0:\n        print "X",\n        else:\n            print ".",\n        print\n            \n  \n 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n/2):\n        print "X .",\n    print\n    for y in range(n/2):\n        print ". X",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2 == 0:\n            for y in range(n):\n                if y % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n        else: 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: \n                print "X",\n            else: \n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if((i+y)%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n//2):\n        for y in range(n//2):\n            print "X .",\n        print\n        for y in range(n//2):\n            print ". X",\n        print 
def sachovnice(n):\n    for i in range(n//2):\n        for j in range(n//2):\n            print "X",".",\n        if n%2!=0:\n            print "X",            \n        print\n        for k in range(n//2):\n            print ".","X",\n 
def sachovnice(n):\n    for i in range(n//2):\n        for j in range(n//2):\n            print "X",".",\n        if n%2!=0:\n            print "X",            \n        print\n        for k in range(n//2):\n            print ".","X",\n 
def sachovnice(n):\nfor i in range(n):\nif i % 2 == 0:\nfor j in range(n):\nif j % 2 == 0:\nprint "X",\nelse:\nprint ".",\nelse:\nfor k in range(n):\nif k % 2 == 1:\nprint "X",\nelse:\np 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i % 2 != 0:\n                if j % 2 != 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n    for y in range(n):\n        if y%2==0:\n        print "X",\n        else:\n            print ".",\n        else:\n            for y in range(n):\n        i 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j)%2 == 0):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==0 and j%2==0 or i%2==1 and j%2==1:\n                print "X",\n            else:\n                print ".",\n            if j==(n-1):\n 
def sachovnice(n):\n    for y in range(n):\n        for i in range(n):\n            if i%2 == 0 and y%2 ==0:\n                print "X",\n            elif i%2 == 1 and y%2 ==1:\n                print "X",\n               \n            els 
def sachovnice(n):\nfor i in range(n):\nfor j in range(n):\nif ((i+j) % 2 == 0):\nprint "X",\nelse:\nprint ".",\nprint 
def sachovnice(n):\n    for y in range(n):\n    for x in range(n):\n        if (x+y) % 2 == 0:\n               print "X",\n            else:\n                print ".",\n    print 
def sachovnice(n):\nfor y in range(n):\nfor x in range(n):\nif (x+y) % 2 == 0:\n print "X",\nelse:\nprint ".",\nprint 
def sachovnice(n):\n    for y in range(n/2):\n        for y in range(n/2):\n            print "X",\n            print ".",\n        print\n        for y in range(n/2):\n            print ".",\n            print "X",\n        print\n 
def sachovnice(n):\n    if n % 2 ==0:\n        k=n/2\n    else:\n        k=(n/2) +0.5\n    for y in range(k):\n        for y in range(k):\n            print "X",\n            print ".",\n        print\n        for y in range(k):\n 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if (j + i) % 2 != 1:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if ((i+y)%2 == 0):\n                print "X",\n            else:\n                print ".",\nprint 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x%2==0 and y%2==0 or x%2!=0 and y%2!=0:\n                print "X",\n            else:\n            print ".",\n    print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x%2==0 and y%2==0 or x%2!=0 and y%2!=0:\n                print"X",\n            else:\n                print".",\n        print\n      \n 
def sachovnice(n):\n        for s in range(n):\n            for r in range(n):\n                if (s+r)%2 == 0:\n                    print "X",\n                else:\n                        print".",\n            print\n 
def sachovnice(n):\n    for riadok in range(n):\n        for stlpec in range(n):\n            if (riadok+stlpec)% 2== 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    \n    for r in range(n):\n        for s in range(n):\n            if (r+s)%2==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if ((x+y)%2==0):\n                print "X",\n            if ((x+y)%2==1):\n                print ".",\n        print\n\n   \n 
def sachovnice(n):\n    for i in range(n/2):\n    for i in range(n/2):\n            print "X .",\n    print\n    for i in range(n/2):\n        print ". X",\n    print\n  \n \n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (x+y) % 2 == 0:\n            print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        if i%2 == 0:\n            \n            for j in range(n):\n                if (j%2)==0:\n                    if j==n:\n                        print "X"\n                    else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i % 2 == 0 and j % 2 == 0) or (i % 2 == 1 and j % 2 == 1):\n                print "X",\n            else:\n                print ".",\nprint\n 
def sachovnice(n):\n    for j in range(n/2):\nfor y in range(n/2):\nprint "X",\nprint ".",\nprint\nfor x in range(n/2):\nprint ".",\nprint "X",\nprint\n 
def sachovnice(n):\nfor j in range(n):\nif j % 2 == 0:\nfor i in range(n):\nif i % 2 == 0:\nprint "X",\nif i % 2 == 1:\nprint ".",\nif j % 2 == 1:\nfor x in range(n):\nif x % 2 == 0:\nprint ".",\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if ((x + y) % 2 == 0):\n                print "X",\n            else:\n                print ".",\nprint 
def sachovnice(n):\n    for y in range(n):\n        radek(n, y % 2)\ndef radek(n, p):\n    for x in range(n):\n        if (x % 2 ==p): print "X",\n        else:print ".",\n    print\n 
def sachovnice(n):\n    sum=0\n    for i in range(n):\n        for y in range(n):\n            if sum%2==0:\n                print "X",\n            else:\n                print ".",\n            sum+=1\n        print 
def sachovnice(n):\n    sum=0\n    for i in range(n):\n        for y in range(n):\n            if sum%2==0:\n                print "X",\n            else:\n                print ".",\n            sum+=1\n        if n%2==0:sum-=1\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if(y+x)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if x % 2 - y % 2 == 0:\n                print "X"\nelse:\n                print "."\nprint 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if x % 2 - y % 2 == 0:\nprint "X",\n            else: \n                print ".",\n\n        print 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n/2):\n        print "X",".",\n    print\n    for y in range(n/2):\n        print ".","X",\n    print\n 
def sachovnice(o):\n    for i in range(o):\n        for j in range(o):\n            if j % 2 == 0:\n                if i % 2==0:\n                    print "X",\n                else:print ".",\n            if j%2 ==1:\n                if 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n\n        print \n 
def sachovnice(n):\n    for i in range(n/2):\n        for j in range (n/2):\n            print ("X"),\n            print ("."),\n        print\n        for j in range (n/2):\n            print ("."),\n            print ("X"),\n        pr 
def sachovnice(n):\n    count = 0\n    while count < n:\n        tmp = 0\n        while tmp <= n:\n            print ("X"),\n            tmp += 1\n            if tmp == n:\n                break\n            print ("."),\n 
def sachovnice(n):\n    count = 0\n    while count < n:\n        tmp = 0\n        while tmp < n:\n            print ("X"),\n            tmp += 1\n            if tmp == n:\n                break\n            print ("."),\n            t 
def sachovnice(n):\n    x = 0\n    for i in range(n):\n        while x != n:\n            for j in range(1):\n                if (i % 2 != 0):\n                    print ".",\n                else:\n                    print "X",\n 
def sachovnice(n):\n    for a in range(n//2):\n        for i in range(n):\n            if i % 2 == 0:\n                print "X", \n            else:\n                print ".", \n        print\n        for y in range(n):\n            if 
def sachovnice(n):\n    for a in range(n//2):\n        for i in range(n):\n            if i % 2 == 0:\n                print "X", \n            else:\n                print ".", \n        print\n        for y in range(n):\n            if 
def sude(n):\n    if n%2 == 0:\n        return True\n    else:\n        return False\n    \ndef sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if sude(radek + sloupec) == True:\n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if(i+y)%2==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range (1,n+1):\n        for j in range (1,n+1):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def radek(n, parita):\nfor j in range(n):\nif (j % 2 == parita): print "X",\nelse: print ".",\nprint\n\ndef sachovnice(n):\nfor i in range(n):\nradek(n, i % 2)\n 
def sachovnice(n):\n    for y in range(n):\n        print\n        for z in range(n):\n            if ((y+z) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i%2==0 and j%2==0 or i%2==1 and j%2==1:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    s= 0\n    for i in range(n):\n        for y in range(n):\n            if s % 2 == 0:\n            print "X",\n            else:\n                print ".",\n            s=s+1\n        print\n        s=s+1 
def sachovnice(n):\n    s= 0\n    for i in range(n):\n        for y in range(n):\n            if s % 2 == 0:\n            print "X",\n            else:\n                print ".",\n            s=s+1\n        print\n        s=s+1 
def sachovnice(n):\n    k = 0\n    for i in range(n):\n        if k % 2 == 0:\n            s=0\n        else:\n            s=1\n        for y in range(n):\n            if s % 2 == 0:\n            print "X",\n            else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i%2==1):\n                if(j%2==1):\n                    print"X",\n                else:\n                    print".",\n            else:\n 
def sachovnice(n):\n    for i in range(n):\n      if(i!=0):\n         print " "\n      for j in range(n):\n         if(i%2==0):\n            if(j%2==0):\n               print "X",\n            else:\n               print".",\n         e 
def sachovnice(n):\n    for i in range(n):\n      if(i!=0):\n         print " "\n      for j in range(n):\n         if(i%2==0):\n            if(j%2==0):\n               print "X",\n            else:\n               print".",\n         e 
def sachovnice(n):\n    for y in range(n):\n      if(y!=0):\n         print ""\n      for z in range(n):\n         if(y%2==0):\n            if(z%2==0):\n               print "X",\n            else:\n               print".",\n         el 
\ndef riadok_sudy(n):\n    for i in range(n):\n        if (i%2==0):\n            if(i==n-1):\n                print"X"\n            else:\n                print"X",\n        else:\n            if(i==n-1):\n            print"."\n 
def sachovnice(n):\n    for i in range(n):\n    for j in range(n):\n        if((i+j)%2==0):\n            print "X",\n        else:\n            print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if ((i%2==0) and (y%2!=0)) or ((i%2!=0) and (y%2==0)):\nprint ".",\n            else:\nprint "X",\n        print\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print "" 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print "" 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print "
def sachovnice(n):\nfor i in range(n):\nfor j in range(n):\nif (i+j) % 2:\nprint ".",\nelse:\nprint "X",\nprint\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j + i) % 2 == 0:\nprint "X",\n            else:\n                print ".",\nprint\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x % 2 == 0:\n                if y % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\n            else:\ 
def sachovnice(n):\nfor i in range(n):\nradek(n, i % 2)\n\n\ndef radek(n, parita):\nfor j in range(n):\nif (j % 2 == parita):\nprint "X",\nelse:\nprint ".",\nprint\n 
def sachovnice(n):\nfor i in range(n):\nfor j in range(n):\nif i % 2 == 0 and j % 2 == 1:\nprint ".",\nelif i % 2 == 0 and j % 2 == 0:\nprint "X",\nif i % 2 == 1 and j % 2 == 0:\nprint ".",\nelif i % 2 == 1 and 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        if i%2==1:\n            for y in range(n/2):\n                print ".",\n                print "X",\n            if n%2!=0:\n                print ".",\n        else:\n            for 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for y in range(n/2):\n                print "X",\n                print ".",\n            if n%2!=0:\n                print "X",\n        else:\n            for 
def sachovnice(n):\n    x=0\n    while x!=n:\n        if x%2==0:\n            for y in range(n):\n                if y%2==0:\n                    print "X",\n                else:\n                    print ".",\n            print\n 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if j%2==1:\n                if i%2==1:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for y in range(n):\n        print "X",\n    for y in range(n/2):\n        print ".",\n        print "X",\n    print\nprint\n 
def sachovnice(n):\n    for y in range(n):\n        if y%2==0:\n            for i in range(int(n/2)):\n                print "X .",\n            if n%2!=0:\n                for y in range(1):\n                    print "X",\n            p 
def sachovnice(n):\n    znaky = []\n    for i in range(n/2 + 1):\n        znaky.append ("X")\n        znaky.append (".")\n    for i in range(n):\n        if i % 2 == 0:\n            for a in znaky[:n]:\n                print a,\n 
def sachovnice(n):\nfor i in range (n):\nfor j in range(n):\nif (i+j)%2 == 0:\nprint "X",\nelse:\nprint ".",\nprint 
def sachovnice(n):\n    c = 0\n    for i in range(n):\n        for j in range(n):\n            if(c % 2 == 0):\n                print "X",\n            else:\n                print ".",\n            c += 1\n        c+=1\n        pri 
def sachovnice(n):\n    krizek = True\n    for i in range(n):\n        for j in range(n):\n            if(krizek):\n                print "X",\n                krizek = False\n            else:\n                print ".",\n 
def sachovnice(n):\n    for i in range(n):\n        if(i % 2 == 0):\n            for i in range(n):\n                if(i %2 == 0):\n                    print "X",\n                else:\n                    print ".",\n        else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2== 0: print"X",\n            else: print".",    \n    \nprint 
def sachovnice(n):\n    for y in range(n/2):\n        a=0\n        while 1>0:\n            print "X",\n            a+=1\n            if a==n:\n                break\n            print ".",\n            a+=1\n            if a==n:\n 
def sachovnice(n):\n    b=0\n    for y in range(n/2):\n        a=0\n        while 1>0:\n            print "X",\n            a+=1\n            if a==n:\n                break\n            print ".",\n            a+=1\n            if 
def sachovnice(n):\n    for i in range(n):\n        for a in range(n):\n            if (i%2 == 0 and a%2 == 0) or (i%2 == 1 and a%2 == 1):\n                print "X",\n            else:\n                print ".",\n        print ""\n 
def sachovnice(n):\n    for i in range(n):\n        for a in range(n):\n            if (i%2 == 0 and a%2 == 0) or (i%2 == 1 and a%2 == 1):\n                print "X",\n            else:\n                print ".",\n        print "
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if (i+j)%2==1:\n                print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for x in range (1, n+1):\n        if x % 2 == 1:                   
def sachovnice(n):\n    for x in range (1, n+1):\n        if x % 2 == 1:                   
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if y % 2 == 1:\n                if x % 2 == 1:\n                    print "X",\n                else: print ".",\n            else:\n                if x 
def sachovnice(n):\n    for i in range(0,n,2):\n    for y in range(0,n,2):\n       print "X .",\n    print\n    for y in range(0,n,2):\n        print ". X",\n    print\n 
def sachovnice(n):\n    x="X"\n    y="."\n    for i in range(1,n):\n        if i%2==0:\n            x+=" X"\n        else:\n            x+=" ."\n    for i in range(1,n):\n        if i%2==0:\n            y+=" ."\n        else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if j%2 == 1:\n                if i%2 == 1:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for l in range(n):\n        for i in range(1,n+1):\n            if (i+l) % 2 == 1:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    sachovnice0 = ""\n    sachovnice1 = ""\n    znaky = ("X ", ". ")\n    for i in range(n): sachovnice0 += znaky[i % 2]\n    for i in range(n): sachovnice1 += znaky[i % 2 - 1]\n    for i in range(n):\n        if i 
def radek_sachovnice(n, lichy):\n    for i in range(1,n+1):\n        if i % 2 == lichy:\n            print "X",\n        else:\n            print ".",\n    print\n\ndef sachovnice(n):\n    for i in range(1,n+1):\n        radek_sacho 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (radek+sloupec)%2==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(1,n+1):\n    for j in range(1,n+1):\n        if ((i-j)%2)==0:\n        print "X",\n            else:\n            print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i-j)%2)!=0:\n                print ".",\n            else:\n                print "X",\n        print 
def chessboard(n):\n    for radek in range(n): \n        for sloupec in range(n):\n            if sloupec%2==0:\n                 if radek%2==0:\n                    print " 
def sachovnice(n):\n    for radek in range(n): \n        for sloupec in range(n):\n            if sloupec%2==0:\n                if radek%2==0:\n                    if sloupec==n-1: \n                        print "X"+""\n 
def sachovnice(n):\n    for radek in range(n): \n        for sloupec in range(n):\n            if sloupec%2==0:\n                if radek%2==0:\n                    if sloupec==n-1: \n                        print "X"+""\n 
def sachovnice(n):\n    for y in range (n):\n        for z in range(n):\n            if (y + z) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    x = "X"\n    v = "."\n    for y in range(n):\n        for i in range(n):\n            if i%2==0:\n                print x,\n            else:\n                print v,\n        print\n        temp = x\n        x 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        if y % 2 == 0:\n            for z in range(n):\n                if z % 2 == 0:\n                    print "X",\n                else:\n                    print "."  ,\n        else:\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if x%2==0 and y%2==0:\n                print "X",\n            if x%2==0 and y%2==1:\n                print ".",     \n            if x%2==1 and y%2==1:\n 
def sachovnice(n):\n    for x in range(n/2):\n        lichy(n)\n        sudy(n)\n    if n%2==1:\n        lichy(n)\n        \ndef lichy(n):\n      
def sachovnice(n):\n    character = "."\n    for y in range(n):\n        if y%2==1:\n            character = "."\n        else:\n            character = "X"\n            \n        for x in range(n):\n            print character,\n 
def sachovnice(n):\n    for y in range(n):\n        print\n        for i in range(n):\n            if (i+y)%2==0:\n                print "X",\n            else:\n                print ".",\n\n 
def sachovnice(n):\n    for y in range(n):\n        if y%2:\n        for d in range(n):\n            if d%2:\n        print "X",\n            else:\n                print ".",\n        else:\n        for t in range(n):\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if (i+y)%2:\n            print ".",\n            else:\n                print "X",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if (y+x) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\nfor i in range(n):\nfor j in range(n):\nif i % 2 == 0:\nif j % 2 == 0:\nprint "X",\nelse:\nprint ".",\nelse:\nif j % 2 == 0:\nprint ".",\nelse:\nprint "X",\nprint 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n/2):\n            if i % 2 != 0:\n                print ".",\n                print "X",\n            else:\n                print "X",\n                print ".",\n 
def sachovnice(n):\n    for i in range (n):\n        for z in range(n):\n            if i%2==0:\n                if z%2==0:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    cislo = 2\n    for i in range(n):\n        for k in range(n):\n            if cislo % 2 == 0:\n                print "X",\n            else:\n                print ".",\n            cislo += 1\n        cislo + 
def sachovnice(n):\n    cislo = 0\n    for radek in range(n):\n        for znak in range(n):\n            if cislo == 0:\n                print "X",\n                cislo += 1\n            elif cislo == 1:\n                print ".",\ 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i + j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        if y % 2 == 1:\n            for j in range(n):\n                if j % 2 == 0:\n                    print ".",\n                else:\n                    print "X",\n        else:\n 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if radek % 2 == 0:\n                if sloupec % 2 == 0:\n                    print "X",\n                else:\n                    print ".",\ 
def sachovnice(n):\n    for i in range (n):\n    for y in range(n):\n        if (i+y)%2==0:\n            print "X",\n        if (i+y)%2==1:\n            print ".",\n    print\n 
def sachovnice(n):\n    for i in range (n):\n        for y in range (n):\n            if i%2==0:\n                if y%2==0:\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    first="X"\n    second="."\n    for y in range(n):\n        second,first=first,second\n        for x in range(n):\n            if x%2==0:\n                print second,\n            else:\n                print fir 
def sachovnice(n):\n    for y in range(n):\n        for i in range (n):\n            if (y + i) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (((i%2==1) and(j%2==1)) or ((i%2==0) and(j%2==0))):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n            for y in range(n):\n                if y%2==1:\n                    print ".",\n                if y%2==0:\n                    print "X",\n        if i%2==1:\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) %2==0:\n                print "X",\n            else:\n                print ".",\n        print\n\n 
def sachovnice(n):\nfor i in range(n):\nif i % 2 == 0:\nfor y in range(n):\nif y % 2 == 0:\nprint "X",\nelse:\nprint ".",\nelse:\nfor y in range(n):\nif y % 2 != 0:\nprint "X",\nelse:\np 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2: print ".",\n            else: print "X",\n        print\n 
def sachovnice(n):\n    for y in range(1,n+1):\n        print\n        for z in range(1,n+1):\n        if (z+y)%2==0:\n            print "X",\n        else:\n            print ".",\n    \n 
def sachovnice(n):\n    if n%2==0:\n        for y in range(n/2):\n            print (n/2)*"X . "\n            print (n/2)*". X "\n    else:\n        for y in range((n-1)/2):\n            print ((n-1)/2)*"X . " + "X"\n            print ( 
def sachovnice(n):\n    for y in range(1,n+1):\nif y % 2 ==1:\nfor j in range(1,n+1):\nif  j% 2 ==1:\nprint "X",\nelse:\nprint ".",\nelse:\nfor j in range(1,n+1):\nif  j% 2 ==1:\nprint ".",\ 
def sachovnice(n):\n    for row in range(n):\n        for col in range(n):\n            if (row + col) % 2 == 0: \n            print "X",\n            else:\n            print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\nif y%2 == 0:\nprint "X . X . X . X . X"\nelse:\nprint ". X . X . X . X ."\n\n    \n       \n 
def sachovnice(n):\nfor y in range(n):\nfor x in range(n):\nif (x+(y%2))%2==0:\nprint "X",\nelse:\nprint ".",\nprint                \n    \n       \n 
def sachovnice(n):\n    for y in range(n):\nif y%2 == 0:\nfor x in range(n/2):\nprint "X",".",\nprint\nelse:\nfor x in range(n/2):\nprint ".","X",  \nprint 
def sachovnice(n):\n     for i in range(1,n+1):\n        for j in range(1,n+1):\n            if ((i+j)%2)==0:\n                print "X",\n            if ((i+j)%2)==1:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0: print("X"),\n            else:print("."),\n        print\n 
def sachovnice(n):\nfor i in range(n):\nif (i % 2 == 0): sudy_radek(n)\nelse: lichy_radek(n)\n\ndef sudy_radek(n):\nfor j in range(n):\nif (j % 2 == 0): print "X",\nelse: print ".",\nprint\n\ndef lichy_radek(n):\nfor j in 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (j+i)%2==0:\n                print "X",\n            else :\n                print ".",\n        print\n     \n 
def sachovnice(n):\n    for row in range(n):\n        for col in range(n):\n            if (col+row)%2==0:\n            print "X",\n            else:\n                print ".",\n        print\n  \n 
def sachovnice(n):\n    for i in range(1, n+1):\n        if i % 2 == 1:\n            print\n            for o in range(1, n+1):\n                if o % 2 == 1:\n                    print "X",\n                else:\n 
def sachovnice(n):\n    for y in range(n):\n        if y % 2 == 1:\n        print "X",\n        else:\n        print ".",\n    print\n    for y in range(n):\n    if y % 2 == 1:\n        print ".",\n        else:\n        print "X" 
def sachovnice(n):\n    for a in range(n):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if y % 
def sachovnice(n):\n    for a in range(n/2):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if y 
def sachovnice(n):\n    for a in range(n/2):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if y 
def sachovnice(n):\n    for a in range(n/2):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if y 
def sachovnice(n):\n    for a in range(n/2):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if y 
def sachovnice(n):\n    for a in range(n/2-1):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if 
def sachovnice(n):\n    for a in range(n/2-1):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if 
def sachovnice(n):\n    for a in range(n/2-1):\n        for y in range(n):\n            if y % 2 == 1:\n                print ".",\n            else:\n                print "X",\n        print\n        for y in range(n):\n            if 
def sachovnice(n): \n    for y in range(n):\n         if y % 2 == 1:\n                    print ".",\n                else:\n                    print "X",\n    print\n    for y in range(n):\n        if y % 2 == 0:\n                    p 
def sachovnice(n):\n    for y in range(n):\n        print "X",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        for y in range(n):\n        if y % 2 == 0:\n            print "X",\n           else: \n            print ".",\nprint\n\n 
def sachovnice(n):\nradek =0\nfor y in range(n):\nfor z in range(n):\nif z % 2 == radek:\nprint "X",\nelse:\nprint ".",\nprint\nif radek == 0:\nradek = 1\nelse:\nradek = 0\nprint\n 
def sachovnice(n):\n    for i in range (n):\n        for j in range (n):\n            if (j+i)%2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(0, n ):\n        for j in range(0, n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y%2 + x%2 ==0) or (y%2 + x%2 ==2):\n                print "X",\n            else:\n                print ".",\n        print\n    print\n 
def sachovnice(n):\n    counter = 0\n    for row in range(n):\n        for col in range(n):\n            if (col + counter) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n        co 
def sachovnice(n):\nfor x in range(1,n+1):\nfor y in range(1,n+1):\nif (x+y) % 2 == 0:\nprint "X",\nelse:\nprint ".",\nprint\n    \n 
def sachovnice(n):\nfor i in range(1,n*n+1):\nif i%2==0:\nprint ".",\nelse: print "X",\nif i%n==0: print\n   \n 
def sachovnice(n):\n    for x in range(1,n+1):\n        for y in range(1,n+1):\nif (x+y) % 2==0:\nprint "X",\nelse: print".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if y%2==0 and i%2==0 or y%2==1 and i%2==1:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for j in range(n):\n        for i in range(n):\n            if (i+j)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n    print\n 
def sachovnice(n):\n    for i in range (n):\n        for j in range (n):\n            if j%2==0:\n                if i%2==0:\n                    print "X",\n                if i%2!=0:\n                    print ".",\n            elif j%2 
def sachovnice(n):\n    p = ""\n    a = "X"\n    b = "."\n    for i in range(n):\n        for y in range (n//2):\n            print a,b,\n        if n % 2 <> 0:\n            print a,\n        print\n        p = a\n        a = b\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        print\n        for y in range(1,n+1):\n            x=(i+y)%2\n            if x==0:\n                print "X",\n            else:\n                print ".", 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if (y+i)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n\n 
def sachovnice(n):\n    odd = True\n    \n    for i in range(n):\n        for y in range(n):\n            if odd:\n                print "X",\n                odd = False\n            else:\n                print ".",\n                o 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if i==j or (i%2==0 and j%2==0) or (i%2!=0 and j%2!=0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n // 2):\n    for y in range(0,n,2):\n        print "X", ".",\n    print\n    for y in range(0,n,2):\n        print ".", "X",\n    print\n 
def sachovnice(n):\nfor j in range(n):\nif j % 2 == 0:\nfor i in range(n):\nif i % 2 == 0:\nprint "X",\nif i % 2 == 1:\nprint ".",\nif j % 2 == 1:\nfor x in range(n):\nif x % 2 == 0:\nprint ".",\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (((x + y) % 2) == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    result = ""\n    for i in range(n):\n        for j in range(n):\n            if (i%2 == 0):\n                if (j%2 == 0):\n                    result += "X"\n                else:\n                    result %2 
def sachovnice(n):\n    for i in range(n):\n        if i % 2==0:\n            if n % 2 ==1:\n                print (n//2)*"X . " + "X"\n            else:\n                print (n//2)*"X . "\n        else:\n            if n % 2==1:\n 
def sachovnice(n):\n    for i in range(n):\n        if i % 2==0:\n            if n % 2 ==1:\n                print (n//2)*"X . " + "X"\n            else:\n                print ((n//2)-1)*"X . " + "X ."\n        else:\n            if 
def sachovnice(n):\n    b = 0\n    a = 0\n    \n    for i in range(n):\n        for y in range(n):\n            if a % 2 == 1 and y == 0:\n                b = 1\n        \n            if b % 2 == 0:\n                print "X",\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for k in range(1, n+1):\n            if (i+k) % 2 == 0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(1,n+1):\n    for j in range(1,n+1):\n        if j % 2 == 0:  \n            print "X",\n            else: \n                print ".",\n    print\n 
def sachovnice(n):\n    for radek in range(n):\n        for sloupec in range(n):\n            if (radek+sloupec)%2==0:\n                print "X",\n            else:\n                print ".",\n        print \n 
def sachovnice(n):\nfor i in range (n):\nfor y in range (n):\nif i%2 == 0:\nif y%2==0:\nprint "X",\nelse: \nprint ".",\nelse: \nif y %2==0:\nprint ".",\nelse:\nprint "X",\nprint 
def sachovnice(n):\nfor i in range(1,n+1):\nfor j in range(1,n+1):\nif (i%2==0 and j%2==0) or (i%2==1 and j%2==1):\nprint "X",\nelse:\nprint ".",\nprint\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if i%2 == 0 and j%2 == 0 or i%2 == 1 and j%2 == 1:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if(i+j)%2==0:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(1,n+1):\n        for x in range(1,n+1):\n            if y % 2 == 0:\n                if x % 2 == 0:\n                    print "X",\n                else: print ".",\n            else:\n 
def sachovnice(n):\nfor i in range(n):\nfor j in range(n):\nif ((i+j) % 2 == 0):\nprint "X",\nelse:\nprint ".",\nprint 
def sachovnice(n):\n    for i in range(1,n+1):\n        if (i % 2 != 0):\n            for i in range(1,n+1):\n                if (i % 2 != 0):\n                    print "X",\n                else:\n                    print ".",\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2==0:\n                print "X",\n            else:\n                print ".",\nprint 
def sachovnice(n):\n    for i in range(n):\n        if (i % 2 ) == 0:\n            for y in range(n):\n                if (y % 2 ) == 0:\n                    print ("X"),\n                else:\n                    print ("."),\n 
def sachovnice(n):\n    for i in range(n):\n        if (i % 2 ) == 0:\n            for y in range(n):\n                if (y % 2 ) == 0:\n                    print ("X"),\n                else:\n                    print ("."),\n 
def sachovnice(n):\n    for i in range(n):\n        if (i % 2 ) == 0:\n            for y in range(n):\n                if (y % 2 ) == 0:\n                    print ("X"),\n                else:\n                    print ("."),\n 
def sachovnice(n):\n    c=0\n    for i in range (n):\n        if c%2==0:\n            for y in range (n):\n                if y%2==0:\n                    print "X",\n                else:\n                    print ".",\n            pri 
def sachovnice(n):\n    for i in range (n/2):\n        for y in range(n/2):\n            print "X .",\n        print\n        for y in range(n/2):\n            print ". X",\n        print\n    print\n 
def sachovnice(n):\n    for y in range(n):\n        print "X",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n    for y in range(n/2):\n        print "X .",\n    print\n    for y in range(n):\n        print ".",\n    print\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for y in range(n/2):\n        print "X .",\n    print\n    for y in range(n/2):\n        print ". X",\n    print\n 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n/2):\n        print "X .",\n    print\n    for y in range(n/2):\n        print ". X",\n    print\n 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n/2):\n        print "X .",\n    print\n    for y in range(n/2):\n        print ". X",\n    print\n 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nif y%2 == 0:\np 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nif y%2 == 0:\np 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nelse y%2 == 0:\n 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nelif:\nprint "X 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nelif:\nprint "X 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nelif:\nprint "X 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nelif:\nprint "X 
def sachovnice(n):\n    for i in range(n/2):\n    for y in range(n):\n        if y%2 == 0:\n        print "X",\nelse:\nprint ".",\n    print\n    for y in range(n):\n        if y%2 == 1:\n        print ".",\nelse:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        radek(n, i % 2)\ndef radek(n, druh):\n    for j in range(n):\n        if (j % 2 == druh): print "X",\n        else: print ".",\n    print\n           \n 
def sachovnice(n):\n    if n%2==0:\n    for i in range(n/2):\n    for y in range(n/2):\n        print "X",\n        print ".",\n    print\n    for y in range(n/2):\n        print ".",\n        print "X",\n    print\n 
def sachovnice(n):\n    if n%2==0:\n    for i in range(n/2):\n    for y in range(n/2):\n        print "X",\n        print ".",\n    print\n    for y in range(n/2):\n        print ".",\n        print "X",\n    print\n 
def sachovnice(n):\nfor y in range(n):\nfor p in range(n):\n\nif (y+p)%2==0:\nprint "X",\nelse:\nprint".",\nprint\n 
def sachovnice(n):\n    for y in range(n):\n        if y % 2 == 0:\n            for i in range(n):\n                if i%2 ==0:\n                    print "X",\n                else:\n                    print ".",\n            print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y) % 2==0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x + y) % 2 == 0: print "X",\n            else: print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if y%2 == 0 and i%2 == 0:\n                print "X",\n            elif i%2!=0 and y%2==0:\n                print ".",\n            elif i%2 == 0 and y%2 ! 
def sachovnice(n):\n    for i in range(n):\n        for y in range(n):\n            if y%2==0 and i%2==0 or y%2==1 and i%2==1:\n                print "X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j)%2!=0:\n                print ".",\n            else:\n                print "X",\n        print\n        \n 
def sachovnice(n):\nfor j in range(n):\nif j % 2 == 0:\nfor i in range(n):\nif i % 2 == 0:\nprint "X",\nif i % 2 == 1:\nprint ".",\nif j % 2 == 1:\nfor x in range(n):\nif x % 2 == 0:\nprint ".",\n 
def sachovnice(n):\nfor line in range(n):\nfor i in range(n):\nif i%2 == line%2:\nprint "X",\nelse:\nprint ".",\nprint\n 
def sachovnice(n):\nfor y in range(n):\nfor z in range(n):\nif (y == 0) or (y%2 == 0):\nif (z == 0) or (z%2 == 0):\nprint "X",\nelse:\nprint ".",\nelif (z == 1) or (z%2 == 1):\nprint "X",\nelse:\np 
def sachovnice(n):\n    for i in range(n//2):\n        for y in range(n):\n            if(y%2==0):\n                print "X",\n            else:\n                print ".",\n        print\n\n        for y in range(n):\n            if(y 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if (i+j) % 2 == 0:\n                print "X",\n            else:\n                print ".",\nprint 
def sachovnice(n):\nfor y in range(1,n+1):\nfor j in range (1,n+1):\nif (y+j)%2==0:\nprint "X",\nelse:   \nprint ".",\nprint\n 
def sachovnice(n):\n    for i in range(n):\n        print\n        for j in range(n):\n            if i%2 == 0:\n                if j%2 == 0:\n                    print "X",\n                else:\n                    print ".",\n 
def sachovnice(n):\n    for riadok in range (n):\n        for stlpec in range (n):\n            if (riadok+stlpec) %2==0:\n                print"X",\n            else:\n                print ".",\n        print 
def sachovnice(n):\nif n % 2 == 0:\nfor y in range(n):\nif y % 2 == 0:\nprint ((n/2)-1)*"X . "+"X ."\nelse :\n    print ((n/2)-1)*". X "+". X"\nelse:\nfor y in range(n):\n    if y % 2 == 0:\nprint ((n/2)-1)* 
def sachovnice(n):\n    for i in range (n):\n        if i%2==0:\n            for y in range(n):\n                if y%2==0:\n                    print "X",\n                else:\n                    print ".",\n        else:\n 
def sachovnice(n):\nx = 0\nfor i in range(n):\nfor j in range(n):\nif x % 2 == 0:\nprint "X",\nelse:\nprint ".",\nx += 1\nprint\nx -= 1 
def sachovnice(n):\nfor i in range(n):\nx = 0\nfor j in range(n):\nif i % 2 == 0:\nif x % 2 == 0:\nprint "X",\nelse:\nprint ".",\nelse:\nif x % 2 == 0:\nprint ".",\nelse:\nprint "X",\n 
def sachovnice(n):\n    for i in range(1,n+1):\n        if n % 2 == 0:\n            if i % 2 == 0:\n                print ". X"*(n/2)\n            else:\n                print "X ."*(n/2)\n        elif n % 2 != 0:\n            if i % 2 
def sachovnice(n):\n    for i in range(1,n+1):\n        if n % 2 == 0:\n            if i % 2 == 0:\n                print ". X "*(n/2-1)+". X"\n            else:\n                print "X . "*(n/2-1)+"X ."\n        elif n % 2 != 0:\ 
def sachovnice(n):\n    for r in range(n):\n        for s in range(n):\n            if (r+s)%2==0:\n                 print"X",\n            else:\n                 print".",\n        print\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2==0:\n        for y in range(n/2):\n           print "X",\n           if y!=n//2:\n              print ".",\n        else:\n            for y in range(n/2):\n           p 
def sachovnice(n):\n    x = True\n    for _ in range(n):\n        for _ in range(n):\n            if x:\n                print "X",\n                x = False\n                \n            else:\n                print ".",\n 
def sachovnice(n):\n    for i in range(n):\n        if i%2 == 0:\n            for y in range(n):\n                if y%2 == 0:\n                print "X",\n                else:\n                    print ".",\n            print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if ((y+x) % 2) == 1:\n                print ".",\n            else:\n                print "X",\n        print 
def sachovnice(n):\n    for y in range(1,n+1):\n        if y%2==0:\n            for x in range (n/2):\n                print ". " + "X",\n        else:\n            for x in range (n/2):\n                print "X " + ".",\nprint 
def sachovnice(n):\n    for i in range(1,n+1):\n        for j in range(1,n+1):\n            if ((i+j)%2==0):\n                print "X",\n            else:\n                print ".",\n        print 
def riadok(zac, leng):\n    if zac:\n        first = "X"\n        second = "."\n    else:\n        first = "."\n        second = "X"\n        \n    for i in range(leng):\n        print first,\n        if first == "X":\n            firs 
def sachovnice(n):\n    for x in range(n):\n        for y in range(n):\n            if(x%2 == 0):\n                if(y%2 == 0):\n                    print "X",\n                else:\n                    print ".",\n            else:\n 
def sachovnice(n):\n    for i in range(n):\n        for j in range(n):\n            if ((i+j) % 2 == 0):\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (x+y)%2 == 0:\n                print "X",\n            else:\n                print ".",\n        print\n 
def sachovnice(n):\n    for x in range(n):\n    for y in range(n):\nif (x+y)%2 == 0:\nprint ".",\n            else:\n                print "X",\n    print\n 
def sachovnice(n):\n    for x in range(1,n+1):\n    for y in range(1,n+1):\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y+x)%2==0: print "X" ,\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y+x)%2==0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n):\n            if (y+x)%2==0:print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    for y in range(n):\n        for x in range(n): \n            if (y+x)%2==0: print "X",\n            else: print ".",\n        print\n 
def sachovnice(n):\n    s = "X . " * ((n // 2) + 2)\n    for i in range(n):\n        print(s[(i%2)*2:(i%2)*2+n*2-1])\n\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n        for j in range(n):\n            if i+j%2==0:\n                print "X",\n            else:\n                print ".",\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
def sachovnice(n):\nfor i in range(n):\n    for j in range(n):\n        if (i+j)%2==0:\n                print ("X"),\n            else:\n                print ("."),\n       print\n 
