#!/usr/bin/env python

import random

prefix = ["{}2", "{}6", "{}A", "{}E"]
random.shuffle(prefix)

hex_digits = list("0123456789ABCDEF" * 11)
random.shuffle(hex_digits)

mac_base = prefix[0] + ":{}{}:{}{}:{}{}:{}{}:{}{}"

print(mac_base.format(*hex_digits[0:11]))