using System;

using System.Threading.Tasks;

using System.Threading;

public class Program

{

    private static Random _random = new Random();

    public static void Main()

    {       

         RunAllProcesses();

    }

    private static void RunAllProcesses()

    {

        var rutting = Task.Run(() =>

        {

           RuttingProcess();

        }).ContinueWith((task) =>

            {

                SomethingThatDependsOnRutting();    

            });

        var parallel = Task.Run(() =>

        {

           SomethingThatCanRunInParallel();

        });

        rutting.Wait();

        parallel.Wait();

    }

    private static void RuttingProcess()

    {

        Console.WriteLine("starting rutting process");

        longWork();

        Console.WriteLine("finished rutting");

    }

    private static void SomethingThatCanRunInParallel()

    {

        Console.WriteLine("starting process that can run parallel with everything");

        longWork();

        Console.WriteLine("finished process running in parallel with everything");

    }

    private static void SomethingThatDependsOnRutting()

    {

        Console.WriteLine("starting process depends on rutting");

        shortWork();

        Console.WriteLine("finished process dependent on rutting");

    }

    private static void shortWork()

    {

        Thread.Sleep(_random.Next(10,50));

    }

    private static void longWork()

    {

        Thread.Sleep(_random.Next(100,300));

    }

}