import base64
import itertools


def decrypt(hui, key):
    s = base64.b64decode(hui)
    return bytes(a ^ b for a, b in zip(s, itertools.cycle(key.encode()))).decode()


def encrypt(hui, key):
    hui = hui.encode()
    key = key.encode()
    result = bytes(a ^ b for a, b in zip(hui, itertools.cycle(key)))
    return base64.b64encode(result)

print(decrypt(encrypt('sup 2ch', 'hui'), 'hui'))