class Q {
    int n;
    boolean value = false;

    synchronized int get() {
        while(!value) {
            try {
                wait();
            } catch (InterruptedException e) {
                System.out.println("Getex1");
            }
        }
        System.out.println("Get " + n);
        value = false;
        notify();
        return n;
    }

    synchronized void put(int n) {
        while(value) {
            try {
                wait();
            } catch (InterruptedException e) {
                System.out.println("Getex2");
            }
        }
        this.n = n;
        value = true;
        System.out.println("Send " + n);
        notify();
    }
}

class Produser implements Runnable {
    Q q;

    Produser(Q q) {
        this.q = q;
        new Thread(this, "Postavwik").start();
    }

    public void run() {
        int i = 0;

        while(i < 20) {
            q.put(i++);
        }
    }
}

class Consumer implements Runnable {
    Q q;

    Consumer(Q q) {
        this.q = q;
        new Thread(this, "Potrebitel'").start();
    }

    public void run() {
        int i = 0;
        while(i < 20) {
            q.get();
        }
    }
}

class PC1 {
    public static void main(String args[]) {
        Q q = new Q();
        new Produser(q);
        new Consumer(q);
    }
}