using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

public class Stack {

    private List<object> objs = new List<Object>();

    public void Push(object value){

        this.objs.Insert(0, value);

    }

    public object Pop(){

        object value = this.objs[0];

        this.objs.RemoveAt(0);

        return value;

    }

    public void Reverse(){

        this.objs.Reverse();

    }

}