private static class DoSmth{

        private final MyClass a;
        private final MyClass b;

        public DoSmth(){
            a = new MyClass("a");
            b = new MyClass("b");
        }

        private void firstThread(){
            synchronized (a){
                b.print();
            }
        }

        private void secondThread(){
            synchronized (b){
                a.print();
            }
        }

    }

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

        DoSmth ds = new DoSmth();

        Thread thread1 = new Thread(new Runnable() {
            @Override
            public void run() {
                ds.firstThread();
            }
        });

        Thread thread2 = new Thread(new Runnable() {
            @Override
            public void run() {
                ds.secondThread();
            }
        });

        thread1.start();
        thread2.start();
        thread1.join();
        thread2.join();
}