import java.util.concurrent.locks.ReentrantLock;

class Teller implements Runnable{
    
    private TallBoks tallBoks;
    private ReentrantLock lock;

    Teller(TallBoks tb, ReentrantLock l) {
        tallBoks = tb;
        lock = l;
    }

    public void run() {
        for (int i = 0; i < 100000; i++) {
            lock.lock();
            try {
                int forrigeTall = tallBoks.hentTall();
                tallBoks.settTall(forrigeTall+1);
            }
            finally {
                lock.unlock();
            }
            
        }
    }
}

class TallBoks {
    ReentrantLock lock = new ReentrantLock();

    private int tall = 0;

    public int hentTall() {
        return tall;
    }

    public void settTall(int t) {
        tall = t;
    }
}

class TestTeller {

    public static void main(String[] args) {
        
        TallBoks tallBoks = new TallBoks();

        ReentrantLock lock = new ReentrantLock();

        Thread t1 = new Thread(new Teller(tallBoks, lock));
        Thread t2 = new Thread(new Teller(tallBoks, lock));

        t1.start();
        t2.start();

        try {
            t1.join();
            t2.join();
        } 
        catch (InterruptedException e) {
            System.err.println(e);
        }

        System.out.println(tallBoks.hentTall());
    }
}