main

class Producer extends Thread{

    public String producerName;
    Buffer<String> buffer;

    public Producer(String name, Buffer<String> buffer) {
        this.producerName = name;
        this.buffer = buffer;
    }

    @Override
    public void run() {
        for(int i = 0; i < 10; i++) {
            System.out.println(producerName + " produces item " + i);
            try {
                buffer.addItem(i + " produced by: " + producerName);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }
}

class Consumer extends Thread{

    public String consumerName;
    Buffer<String> buffer;

    public Consumer(String name, Buffer<String> buffer) {
        this.consumerName = name;
        this.buffer = buffer;
    }

    @Override
    public void run() {
        for(int i = 0; i < 10; i++) {
            String item = null;
            try {
                item = buffer.getItem();
                System.out.println("The item \"" + item + "\" consumed by " + consumerName);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }
}

public class Sync {

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

        Buffer<String> buffer = new Buffer<>(5);

        HashSet<Thread> producers = new HashSet<>();
        HashSet<Thread> consumers = new HashSet<>();

        for(int i = 0; i < 10; i++) {
            producers.add(new Producer("Producer"+i, buffer));
            consumers.add(new Consumer("Consumer"+i, buffer));
        }

        consumers.forEach(Thread::start);
        producers.forEach(Thread::start);

        for (Thread producer : producers) {
            producer.join();
        }

        for (Thread consumer : consumers) {
            consumer.join();
        }
    }

}