using System;

        class Base

        {

        public void Execute() { Console.WriteLine("Base.Execute"); }

        }

        class Derived : Base

        {

        public new void Execute() { Console.WriteLine("Derived.Execute"); }

        }

        class Program

        {

        static void Main(string[] args)

        {

        Base b = new Base();

        b.Execute();

        b = new Derived();

        b.Execute();

        }

}