#!/bin/python

import os

import re

def GetMac():

    if os.name == 'nt':

        try:

            ret = ''

            CmdLine = 'ipconfig /all'

            r = os.popen(CmdLine).read()

            if r:

                L = re.findall('Physical Address.*?([0-9,A-F]{2}-[0-9,A-F]{2}-[0-9,A-F]{2}-[0-9,A-F]{2}-[0-9,A-F]{2}-[0-9,A-F]{2})', r)

                if len(L) > 0:

                    ret = L[0]

        except:

            pass

        

    elif os.name == "posix":

        try:

            ret = ''

            CmdLine = 'ifconfig'

            r = os.popen(CmdLine).read()

            if r:

                L = re.findall('HWaddr.*?([0-9,A-F]{2}:[0-9,A-F]{2}:[0-9,A-F]{2}:[0-9,A-F]{2}:[0-9,A-F]{2}:[0-9,A-F]{2})', r)

                if len(L) > 0:

                    ret = L[0]

        except:

            pass

    else:

        pass

    return ret

if __name__ == '__main__':

    mac = GetMac()

    print mac

    m=raw_input()