public class TwoThread {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
Convect convect = new Convect();
TreeSet<Integer> numbers = new TreeSet<>();
Object lock = new Object();
Object lock2 = new Object();

public static void main(String... args) throws InstantiationException,
        IllegalAccessException {

    /*
     * one two three four five six seven
     */

    TwoThread m = new TwoThread();
    m.make();

}

void addNumber() {
    synchronized (lock) {
        try {
            while (true) {
                numbers.add(convect.toNumber(br.readLine()));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

void removeNumber() {
    synchronized (lock2) {
        while (true) {
            try {
                if (numbers.size() != 0) {
                    int i = numbers.first();
                    numbers.remove(i);
                    System.out.println(i);
                }
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

void make() {
    Thread t1 = new Thread(new Runnable() {

        @Override
        public void run() {
            addNumber();
        }
    });

    Thread t2 = new Thread(new Runnable() {

        @Override
        public void run() {
            removeNumber();
        }
    });

    /*
     * try { t1.join(); t2.join(); } catch (InterruptedException e) {
     * e.printStackTrace(); }
     */

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