#!/usr/bin/env python3
from hashlib import sha1
from sys import argv
m = sha1()
m.update(argv[1].encode())
m.update(b"-")
m.update(argv[2].encode())
d = m.digest()
addr = [ (d[i]+d[i+6]) % 256 for i in range(6) ]
addr[0] &= 0xfe
addr[0] |= 0x02
print(':'.join(map(lambda x : ("00"+hex(x)[2:])[-2:],addr)))