public static void main(String[] args) throws Exception {
		ParkingCounter counter = new ParkingCounter(5);

		Sensor1 sensor1 = new Sensor1(counter);
		Sensor2 sensor2 = new Sensor2(counter);

		Thread thread1 = new Thread(sensor1);
		Thread thread2 = new Thread(sensor2);

		thread1.start();
		thread2.start();

		thread1.join();
		thread2.join();

		System.out.printf("Main: Number of cars: %d\n", counter.get());

		System.out.printf("Main: End of the program.\n");
	}