using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

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

        // Add items for testing

        planets.Enqueue("Mercury");

        planets.Enqueue("Venus");

​

        // Count : Total number of items in the collection.

        Console.WriteLine(planets.Count);

​

    }

}