using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        string[] Animals = {"Dog", "Cat", "Fish", "Rabbit"};

        int AnimalsLength = Animals.Length;

        Console.WriteLine(AnimalsLength);

        Console.WriteLine(Animals[3]);

        List<String>animals = new List<String>{"Dog"};

        animals.Add("Cat");

        animals.Add("Fish");

​

        int animalsLength = animals.Count;

        Console.WriteLine(animalsLength);

        animals.Clear();

        animalsLength = animals.Count;

        Console.WriteLine(animalsLength);

        Stack<String>Animals2 = new Stack<String>();

        Animals2.Push("Dog");

        Animals2.Push("Cat");

        int Animals2Length = Animals2.Count;

        Console.WriteLine(Animals2Length);

        Console.WriteLine(Animals2.Peek());

        Console.WriteLine(Animals2.Pop());

        Console.WriteLine(Animals2.Peek());

        Animals2.Push("Fish");

        Console.WriteLine(Animals2.Peek());

        Queue<String>animals2 = new Queue<String>();

        animals2.Enqueue("Dog");

        animals2.Enqueue("Cat");

        animals2.Enqueue("Rabbit");

        animals2.Enqueue("Fish");

        animals2.Enqueue("Parrot");

        int animals2Length = animals2.Count;

        Console.WriteLine(animals2Length);

        Console.WriteLine(animals2.Peek());

    }

}