111336 шифр Цезаря

def Cezar(s,k):
    res = ''
    k %= 26
    for x in s.strip():
        if ord('a') <= ord(x) <= ord('z'):
            new_code = ord(x)+k
            if new_code > ord('z'):
                new_code -= 26

            res += chr(new_code)
        elif ord('A') <= ord(x) <= ord('Z'):
            new_code = ord(x)+k
            if new_code > ord('Z'):
                new_code -= 26
            res += chr(new_code)
        else:
            res += x
    return res

file = open('input.txt', 'r')
s = file.readline()
k = 0
while s:
    k += 1
    print(Cezar(s,k))
    s = file.readline()