class Bag {

    private int sweets, in, out;
    public boolean occupied = false;
    public Bag() {
        sweets = in = out = 0;

    }

    public synchronized void addItem() {

        sweets++;
        in++;
    }

    public synchronized void removeItem() {

        sweets--;
        in--;
    }

    public synchronized void printDelta() {

        System.out.println("Delta = " + (in-out-sweets) + " Sweets = " + sweets);
    }

}
class Parent extends Thread {

    private Bag bag;
    public Parent(Bag bag) {
        this.bag = bag;
    }

    public void run() {

        while(bag.occupied) {
            try {
                wait();
            } catch (InterruptedException e) { }
        }

        bag.addItem();
        bag.occupied = true;
        notifyAll();
    }
}

class Child extends Thread {

    private Bag bag;
    public Child(Bag bag) {
        this.bag = bag;
    }

    public void run() {
        while(!bag.occupied) {
            try {
                wait();
            } catch (InterruptedException e) { }
        }

        bag.removeItem();
        bag.occupied = false;
        notifyAll();
    }
}

public class Sweets {

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

        Bag bag = new Bag();
        Child cthread = new Child(bag);
        Parent pthread = new Parent(bag);

        cthread.start();
        pthread.start();

        while(true) {
            Thread.sleep(2000);
            bag.printDelta();
        }
    }
}