def bin2str(s1):
	"""
	Convert a binary string to corresponding ASCII string
	"""
	for i in s1:
		assert i == "0" or i == "1"
	bin_list = [int(s1[i:i+8], 2) for i in range(0, len(s1), 8)]
	for i in bin_list:
		assert i < 256
	bin_list = [chr(i) for i in bin_list]
	return "".join(bin_list)