class Q {
  private int v;
  private boolean valueSet = false;
  
  synchronized public void put(int v) {
    while (valueSet) 
      try {
        wait();
      }
      catch (InterruptedException e)  {
        System.out.println("interrupted in Q.put()");
        return;
      }
    this.v = v;
    valueSet = true;
    System.out.println("put " + v);
    notify();
  }
  
  synchronized public int get() {
    while (!valueSet)
      try {
        wait();
      }
      catch (InterruptedException e)  {
        System.out.println("interrupted in Q.get()");
        return 0;
      }
    valueSet = false;
    notify();
    return v;
  }
}

class Producer implements Runnable {
  private Q q;
  
  Producer(String name,Q q) {
    this.q = q;
    new Thread(this, name).start();
  }
  
  public void run() {
    for (int i = 0; i <= 10; i++) {
      q.put(i);
    }
  }
}

class Consumer implements Runnable {
  private Q q;
  
  Consumer(String threadName, Q q) {
    this.q = q;
    new Thread(this, threadName).start();
  }
  
  public void run() {
    while (true) {
      System.out.println("consumer got " + q.get());
    }
  }
}

class Main {
  public static void main(String[] args) {
    Q q = new Q();
    new Producer("producer", q);
    new Consumer("consumer", q);
  }
}

class Q {
  private int v;
  private boolean valueSet = false;
  private final Object lockV = new Object();
  
  public void put(int v) {
    synchronized(lockV) {
      while (valueSet) 
        try {
          lockV.wait();
        }
        catch (InterruptedException e)  {
          System.out.println("interrupted in Q.put()");
          return;
        }
      this.v = v;
      valueSet = true;
      lockV.notify();
    }
  }
  
  public int get() {
    synchronized(lockV) {
      while (!valueSet)
        try {
          lockV.wait();
        }
        catch (InterruptedException e)  {
          System.out.println("interrupted in Q.get()");
          return 0;
        }
      valueSet = false;
      lockV.notify();
      return v;
    }
  }
}