public class Task230725 {
    private static volatile boolean flag = true;

    public static void main(String[] args) {
        new Thread(() -> {
            while (flag) {
                // empty loop
            }
            System.out.println("Thread stopped");
        }).start();

        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        
        flag = false;
        System.out.println("Main stopped");
    }
}

public class Task240725 {
    private static synchronized void print(String msg) {
        System.out.print(msg + " ");
    }

    public static void main(String[] args) {
        Thread t1 = new Thread(() -> print("Hello"));
        Thread t2 = new Thread(() -> print("World"));
        
        t1.start();
        t2.run();
        
        try {
            t1.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}