import java.util.HashSet;
import java.util.concurrent.Semaphore;
public class VoleyballTournament {
    public static void main(String[] args) throws InterruptedException {
        HashSet<Player> threads = new HashSet<>();
        for (int i = 0; i < 60; i++) {
            Player p = new Player(i);
            threads.add(p);
        }
        // run all threads in background
        for (Player t: threads)
        {
            t.start();
        }
        // after all of them are started, wait each of them to finish for maximum 2_000 ms
        for(Player t: threads)
        {
            t.join(2000);
        }
        // for each thread, terminate it if it is not finished
        for (Player t: threads) {
            if (t.isAlive()) {
                t.interrupt();
                System.out.println("Possible deadlock");
            }
        }
        System.out.println("Tournament finished.");

    }
}

class Player extends Thread {
    int tdx;
    static Semaphore sala=new Semaphore(12);
    static Semaphore soblekuvalna=new Semaphore(4);
    static int count=0;
    static int gCount=0;
    static Semaphore clock=new Semaphore(1);
    static Semaphore canPlay=new Semaphore(0);
    static Semaphore eHall=new Semaphore(0);
    static boolean flag=false;

    public Player(int tdx)
    {
        this.tdx=tdx;
    }
    public void execute() throws InterruptedException {
        // at most 12 players should print this in parallel
        sala.acquire();
        System.out.println("Player inside.");
        // at most 4 players may enter in the dressing room in parallel
        soblekuvalna.acquire();
        System.out.println("In dressing room.");

        clock.acquire();
        count++;
        gCount++;
        if(count==4)
        {
            count=0;
            eHall.release(4);
            flag=true;
        }
        Thread.sleep(10);// this represent the dressing time
        if(gCount==12)canPlay.release(12);
        if(flag)
        {
            soblekuvalna.release(4);
            flag=false;
        }
        clock.release();
        eHall.acquire();
        canPlay.acquire();
        // after all players are ready, they should start with the game together
        System.out.println("Game started.");
        Thread.sleep(100);// this represent the game duration
        clock.acquire();
        --gCount;
        if(gCount==0)
        {
            System.out.println("game finished");
            sala.release(12);
            eHall.drainPermits();
            canPlay.drainPermits();
            count =0;
        }
        else {
            System.out.println("Player done.");
        }// only one player should print the next line, representing that the game has finished
        clock.release();
    }

    public void run()
    {
        try
        {
            execute();
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }

    }
}