using System;

using System.Collections.Generic;

using System.Threading;

using System.Linq;

public class Program

{

    public static void Main()

    {

        const int N = 2000;

        List<Thread> threads = new List<Thread>(N);

        var results = new bool[N];

​

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

        {

            int iCopy = i;

​

            var t = new Thread(() =>

                {

                    Thread.Sleep(1000);

                    results[iCopy] = true;

//                    Console.WriteLine($"Thread {iCopy}");

                })

                {IsBackground = true};

            threads.Add(t);

​

            t.Start();

        }

​

        Console.WriteLine("Done");

        Thread.Sleep(3000);

        Console.WriteLine(results.All(q=>q));

    }

}