using System;

using System.Collections;                   

public class Program

{

    public static void Main()

    {

        Stack s= new Stack();

        s.Push("a");

        s.Push("b");

        s.Push("c");

        s.Push("d");

​

        foreach(Object o in s)

            Console.WriteLine(o.ToString());

        Console.WriteLine(s.Peek());

        //Console.WriteLine(s.Pop());

foreach(Object o in s)

            Console.WriteLine(o.ToString());

                    Console.WriteLine(s.Count);

​

    }

}