moth/doc/2010-10-NMT/posters/decode

#! /usr/bin/python

import sys

def xor(s, t):
    return ''.join(chr(ord(a) ^ ord(b)) for (a,b) in zip(s,t))

acc = None
for line in sys.stdin:
    l = line.strip().decode('hex')
    print l
    if not acc:
        acc = l
    else:
        acc = xor(acc, l)
print acc