import sys

ciphertext = chr(0xcc) + chr(0xdb) + chr(0xff) + chr(0xff) + "%x"*51 + "%n"

c = list(ciphertext)
c = [ord(i) for i in c]
cl = len(c)

key = [-3, 4, -7, 2, 0, 8, -7, -7, 8, 6, -5, -5, 8, 4, 4]

diff = key * (1 + len(c)/15)

plain = [i-j for i,j in zip(c,diff)]

plaintext = ""

for i in plain:
    i = i % 256
    plaintext += chr(i)

sys.stdout.write(plaintext)
