# expect shift <26 and shift > -26

def caesar_encode(text, shift):
    cipher = ""
    for i in range(len(text)):
        ord_num = ord(text[i])+shift
        if (ord_num > ord('z')) or (ord_num < ord('a')):
            ord_num -= 97
            ord_num = ord_num % 26
            ord_num += 97
        cipher += chr(ord_num)
    return cipher


def caesar_decode(cipher, shift):
    text = ""
    for i in range(len(cipher)):
        ord_num = ord(cipher[i]) - shift
        if ord_num < ord('a'):
            ord_num += 26
        if ord_num > ord('z'):
            ord_num -= 26
        text += chr(ord_num)
    return text


print(caesar_encode("ahoj",3))
print(caesar_decode("dkrm",3))