using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Collections.Specialized;

​

public class Program

{

    public static void Main()

    {

        Stack<string> books = new Stack<string>();

        books.Push("Essential C# 4.0");

        books.Push("Visual C Sharp 2012 Step by Step");

        books.Push("Professional C 2012 and .NET 4.5");

        foreach (var book in books)

        {

            Console.WriteLine(book);

        }

​

        Console.WriteLine();

        string topBook = books.Pop();

        Console.WriteLine(topBook);

​

    }

}