class Puffer {
	
	//Only one thread can access the synchronized method at a time
	public synchronized void criticalSection(){
		Thread current = Thread.currentThread();
		System.out.println("Enter the critical section: " + current.getName());
		try {
			Thread.sleep(1000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		System.out.println("Leave the critical section: " + current.getName());
	}
}

class MyRunnable implements Runnable {

	private Puffer puffer;
	
	public MyRunnable(Puffer puffer) {
		super();
		this.puffer = puffer;
	}

	@Override
	public void run() {
		puffer.criticalSection();
	}
	
}

public class SynchronizedMain {

	public static final int N = 10;
	
	public static void main(String[] args) {
		Puffer puffer = new Puffer();
		for(int i=0; i<N; i++) {
			Thread t = new Thread(new MyRunnable(puffer));
			t.setName("Thread " + i);
			t.start();
		}
	}

}