# standard imports
import logging
import sys

# external imports
import sha3

logging.basicConfig(level=logging.WARNING)
#logging.basicConfig(level=logging.DEBUG)
logg = logging.getLogger()

if __name__ == '__main__':
    f = open(sys.argv[1], 'r')
    z = b''
    for i in range(32):
        z += b'\x00'
    while True:
        l = f.readline().rstrip()
        if l == '':
            break
        logg.debug('line {}'.format(l))
        h = sha3.keccak_256()
        h.update(l.encode('utf-8'))
        r = h.digest()
        z = bytes([a ^ b for a, b in zip(r, z)])
        logg.debug('{} -> {}'.format(r.hex(), z.hex()))
    f.close()

    print(z[:4].hex())