using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var x = new Jump();

        x.jumpId = 2;

        var c = new Jumper();

        c.jumpId = x.jumpId;

        c.jumperId = c.jumpId * 10;

        Console.WriteLine(c.jumperId);

    }

    class Jump

    {

        public int jumpId {get;set;}

    }

    class Jumper: Jump

    {

        public int jumperId {get;set;}

    }

}