static void Main(string[] args)
        {
            Console.WriteLine("chatting app");
            ChatApp chatApp = new ChatApp();

            chatApp.Start();
            Console.ReadKey();
        }
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            ChatApp chatApp = new ChatApp();

            chatApp.Start();
            Console.ReadKey();
        }