using System;
namespace App
{
    public class Test
    {
        public delegate int delegateTest(int x);

        public static int square(int x)
        {
            return x * x;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
          Test.delegateTest del = Test.square;

          System.Console.WriteLine(del(20));
        }
    }
}