using System;

using System.Threading;

​

class Racer

{

    private readonly string name;

    public Racer(string name)

    {

        this.name = name;

    }

​

    public void Run()

    { 

        Thread.Sleep(100);

        Console.Write(name);

    }

​

    static void Main(string[] args)

    {

        Thread t1 = new Thread(new Racer("1").Run);

        Thread t2 = new Thread(new Racer("2").Run);

        Thread t3 = new Thread(new Racer("3").Run);

        Thread t4 = new Thread(new Racer("4").Run);

        Thread t5 = new Thread(new Racer("5").Run);

​

        t5.Start();

        t3.Start();

        t1.Start();

        t3.Join();

        t2.Start();

        t1.Join();

        t4.Start();

        t2.Join();

        t4.Join();

        t5.Join();

    }

}