public class Main {
    public static void main(String[] args) {
       Thread t1 = new Thread(new MyThread(1));
       Thread t2 = new Thread(new MyThread(2));
       t1.start();
       t2.start();
    }
}
class MyThread implements Runnable {
    int id;
    public MyThread(int _id) {
        id = _id;
    }
    @Override
    public void run() {
        for(int i = 0; i < 20; i++) {
            System.out.println("Thread " + id + " "  + i);
        }
    }
}