static void Main(string[] args) { PrintNum printNum = new PrintNum(); for (int i = 0; i < 3; i++) { Thread temp = new Thread(new ThreadStart(printNum.PrintOddNum)); temp.Start(); } lock (printNum) { Console.WriteLine("Main thread will delay 5 seconds"); Thread.Sleep(5000); Console.WriteLine("Main thread already delayed 5 seconds, Press any key to exit."); } Console.ReadLine(); }