import java.util.BitSet;
import java.util.concurrent.Semaphore;

public class Main {

     private static final int THREADS = 4;
     private static final int N= 60;
     public static Semaphore semaphore = new Semaphore(1);


     public static BitSet set;
     public static int size;
     public static int x;
     public static int maximum;

        public Main(int x) {
            size = x + 1;
            set = new BitSet(size);
            set.flip(2, size);
            maximum = (int) Math.floor(Math.sqrt(size)+1);


        }

    public static void main(String[] args) throws InterruptedException {

                Main bitSetSieveMain = new Main(N);
                Thread [] threadsTab = new Thread[THREADS];

                for(int i=0; i<threadsTab.length; i++) threadsTab[i] = new Thread(new Sito(i));

                long start = System.nanoTime();




                for(int i=0; i<threadsTab.length; i++)
                {
                    threadsTab[i].start();

                }
                for(int i=0; i<threadsTab.length; i++)
                {
                    threadsTab[i].join();
                }

                long time = System.nanoTime() - start;



                System.out.println(time/10000  + " nano seconds to perform " + set.length() + " numbers " + bitSetSieveMain);
                System.out.println(Main.set.cardinality());



    }





    public String toString() {
        return set.toString();
    }



}