using System;
using System.Threading;

class EventTst {
    static AutoResetEvent e1 = new AutoResetEvent(false);
    static AutoResetEvent e2 = new AutoResetEvent(false);

    public static void Main() {
        try {
            Thread thread1 = new Thread(
                new ThreadStart(PrintOdds)
            );
            Thread thread2 = new Thread(
                new ThreadStart(PrintEvens)
            );

            thread1.Start();
            thread2.Start();

            thread1.Join();
            thread2.Join();
        } finally {
            e1.Close();
            e2.Close();
        }
    }

    static void PrintOdds() {
        for (int i = 1; i <= 999; i += 2) {
            Console.WriteLine("{0} --", i);
            e1.Set();     // Set e1 in the signal state
            e2.WaitOne(); // Wait until even number is printed
        }
    }

    static void PrintEvens() {
        for (int i = 2; i <= 1000; i += 2) {
            e1.WaitOne(); // Wait until odd number is printed
            Console.WriteLine("-- {0}", i);
            e2.Set();     // Set e2 in the signal state
        }
    }
}