using System;

using System.Threading;

using System.Threading.Tasks;

​

public static class Program

{

    public static async Task Main()

    {

        var cts = new CancellationTokenSource();

        Print("1");

        var task = Task.Run(async () =>

        {

            Print("2");

            try { await Task.Delay(Timeout.Infinite, cts.Token); }

            catch (OperationCanceledException) { }

            Print("4");

            Thread.Sleep(1000);

            Print("5");

        });

        Thread.Sleep(1000);

        Print("3");

        cts.Cancel();

        Print("6");

        await task;

​

        static void Print(object value)

        {

            Console.WriteLine($@"{DateTime.Now:HH:mm:ss.fff} [{Thread.CurrentThread

                .ManagedThreadId}] > {value}");

        }

    }

}