public static void Main()
{
Distributor d = new Distributor("D");
Subscriber a = new Subscriber("a");
d.Subscribe(a);
Thread.Sleep(1000);
d.Post("First message");
Subscriber b = new Subscriber("b");
d.Subscribe(b);
Thread.Sleep(1000);
d.Post("Second message");
Subscriber c = new Subscriber("c");
d.Subscribe(c);
Thread.Sleep(1000);
d.Post("Third message");
Console.WriteLine("done");
Console.ReadLine();
}