[JAVA] Simple solution
\nclass Foo {\n    \n    CountDownLatch latchForSecond = new CountDownLatch(1);\n    CountDownLatch latchForThird = new CountDownLatch(1);\n\n    public Foo() {
```\nclass Foo {\n    \n    CountDownLatch latchForSecond = new CountDownLatch(1);\n    CountDownLatch latchForThird = new CountDownLatch(1);\n\n    public Foo() {\n        \n    }\n\n    public void first(Runnable printFirst) throws InterruptedException {\n        // printFirst.run() outputs "first". Do not change or remove this line.\n        printFirst.run();\n        latchForSecond.countDown();\n    }\n\n    public void second(Runnable printSecond) throws InterruptedException {\n        latchForSecond.await();\n        // printSecond.run() outputs "second". Do not change or remove this line.\n        printSecond.run();\n        latchForThird.countDown();\n    }\n\n    public void third(Runnable printThird) throws InterruptedException {\n        latchForThird.await();\n        // printThird.run() outputs "third". Do not change or remove this line.\n        printThird.run();\n    }\n}\n```
['Java']