import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

class CountMonitor {
    private Lock lock = new ReentrantLock();
    private int sharedCounter = 0;

    public void increment() {
        lock.lock();
        try {
            sharedCounter++;
        }
        finally {
            lock.unlock();
        }
    }
    public int getCounter() {
        return sharedCounter;
    }
}