#!/usr/bin/python3

from argparse import ArgumentParser
from re import match
from sys import exit

parser = ArgumentParser(description='mac to ip6 conversion')
parser.add_argument('mac', help='MAC address')
args = parser.parse_args()

m = match('^' + ('([0-9a-fA-F]{1,2}):' * 6)[:-1] + '$', args.mac)
if not m:
	print('invalid mac address')
	parser.print_usage()
	exit(-1)
mac = list(map(lambda s: int(s, 16), m.groups()))

mac[0] |= 2;

print("::%02x%02x:%02xff:fe%02x:%02x%02x" % tuple(mac))