Simple Hello World C#

HelloWorld.cs

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    namespace HelloWorld
    {
        class Program
        {
            static void Main(string[] args)
            {
                Console.WriteLine("Hello World!");
                Console.ReadLine();
            }
        }
    }