using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        Match("25004920");

        Match("25004982");

        Match("25004918");

        Match("25004981");

        Match("250049fg");

    }

    static void Match(string input)

    {

        var pattern = "250049(?!81|20)..";

        Console.WriteLine(input + " " + (Regex.IsMatch(input, pattern) ? "matche" : "ne matche pas"));

    }

}