import java.util.concurrent.*;
import java.util.*;

class MyRunnable implements Runnable {
    protected int id;
    
    MyRunnable(int id) {
        this.id = id;
    }
    
    public void run() {
        try {
            String name = Thread.currentThread().getName();
            System.out.println(id + " -- " + name);
            Thread.sleep(10);
        } catch (InterruptedException e) {
            System.out.println("interrupted!");
        }
    }
}

class Main {
    public static void main(String[] args) {
        ExecutorService es = Executors.newFixedThreadPool(4);
        for (int i = 0; i < 10; i++) {
            es.execute(new Thread(new MyRunnable(i)));
        }
        es.shutdown();
        System.out.println("done!");
    }
}