public class Main {
    public static void main(String[] args) {
        MyThread t1 = new MyThread(1);
        MyThread t2 = new MyThread(2);
       t1.start();
       t2.start();
    }
}
class MyThread extends Thread {
    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);
        }
    }
}