using System;
using System.Text;
using System.Text.RegularExpressions;

namespace parsingxml
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Give me a mac address: ");

            string input = Console.ReadLine();
            input = input.Replace(" ", "").Replace(":","").Replace("-","");

            Regex r = new Regex("^[a-fA-F0-9]{12}$");


            if (r.IsMatch(input))
            {
                Console.Write("Valid Mac");
            }
            else
            {
                Console.Write("Invalid Mac");
            }
            Console.Read();
        }
    }
}