import re

print("请输入mac地址 ，回车结束输入")
L = []
while  True:
	
	mac = input("请输入mac地址 :")

	if mac == "":
		break

	L.append(mac)

for  mac in range(len(L)):
	m = re.match('^(([0-9a-fA-F]{2}:){5})([0-9a-fA-F]{2})$',mac)
	if  m  is not None:
		print(m.group())