C# - Semaphore

using System.Threading;

namespace Semaphore_Demo
{
    class Program
    {
        static Semaphore semaphore = new Semaphore(3, 3);

        static void Main(string[] args)
        {
            for (int i = 0; i < 20; i++)
            {
                new Thread(DoSomething).Start(i);
            }
            Console.Read();
        }
        static void DoSomething(object id)
        {
            Console.WriteLine(id + " wants to access the semaphore");
            semaphore.WaitOne();
            Console.WriteLine(id + " as successed to access the semaphore");
            Thread.Sleep(2000);
            Console.WriteLine(id + " is about to leave the smeaphore");
            semaphore.Release();
        }
    }
}