import sys

file_in1 = open(sys.argv[1], "rb").read()
file_in2 = open(sys.argv[2], "rb").read()
file_out = bytearray()

for i in range(0,len(file_in1)):
	file_out.append(file_in1[i])
	file_out.append(file_in2[i])

open(sys.argv[3], "wb").write(file_out)