using System;

using System.Threading;

​

public class Program

{

    static Mutex mutexObj = new Mutex();

    static int x=0;

    static void Main(string[] args)

    {

        for (int i = 0; i < 5; i++)

        {

            Thread myThread = new Thread(Count);

            myThread.Name = $"Поток {i}";

            myThread.Start();

        }

        Console.ReadLine();

    }

    public static void Count()

    {

        mutexObj.WaitOne();

        x = 1;

        for (int i = 1; i < 9; i++)

        {

            Console.WriteLine($"{Thread.CurrentThread.Name}: {x}");

            x++;

            Thread.Sleep(100);

        }

        mutexObj.ReleaseMutex();

    }

}