using System;

​

public abstract class Object {

​

    public abstract void Move(); 

}

​

public class Hero : Object {

​

    public void Fight_Back(){

        Console.WriteLine("The hero fights back.");

    }

    public override void Move(){

        Fight_Back();

    }

​

}

​

public class Monster : Object {

​

    public void Attack(){

        Console.WriteLine("The monster attacks.");

    }

    public override void Move() {

        Attack();

    }

​

}

​

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Hero H1 = new Hero();

        H1.Move();

        H1.Fight_Back();

        Monster M1 = new Monster();

        M1.Move();

        M1.Attack();

    }

}