'''
Prints the XOR of two hex strings as input arguments

Author: Tim Pierson, Dartmouth CS55, Winter 2021
		code is from Wenliang Du https://github.com/kevin-w-du/BookCode/blob/master/Encryption/xor.py
Usage: python3 xor.py <Hex string1> <Hex string2>
'''
from sys import argv
script, first, second = argv
aa = bytearray.fromhex(first)
bb = bytearray.fromhex(second)
xord = bytearray(x^y for x,y in zip(aa,bb))
print(xord.hex())