using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Queue<string> Cola = new Queue<string>();

        Cola.Enqueue ("Primero");

        Cola.Enqueue ("Segundo");

        Cola.Enqueue ("Tercero");

        Cola.Enqueue ("Cuarto");

        while (Cola.Count>=1)

        {

            Console.WriteLine(Cola.Dequeue());

        }

    }

}