import java.util.concurrent.Semaphore;

public class ATM {
	private static int balance = 0;
	private static int deposits = 0;
	private static int withdrawals = 0;
	static Semaphore semaphore = new Semaphore(1); // only one thread in the CS
	
	public void deposit() {
		try {
		    semaphore.acquire();
    		balance ++;
    		semaphore.release();
		}
		catch (java.lang.InterruptedException e) {}
	}
	public void withdraw() {
		try {
		    semaphore.acquire();
    		balance --;
    		semaphore.release();
		}
		catch (java.lang.InterruptedException e) {}

	}
	public int getBalance() {
      		return balance;
	}
	public static void main(String[] args) {
		ATM atm = new ATM ();
		Thread A = new Thread (new Runnable() {
    			public void run (){
        				while (true) {
            				atm.deposit();
            				deposits ++;
            				try {
            					Thread.currentThread().sleep((int)(Math.random() * 1000));
            				} catch (InterruptedException e) {}
            				System.out.println ("Thread A have made " + deposits + " deposits and see the balance as " + balance);
        				}
    			}
		});
		Thread B= new Thread (new Runnable() {
    			public void run (){
        				while (true) {
            				atm.withdraw();
            				withdrawals++;
            				try {
            					Thread.currentThread().sleep((int)(Math.random() * 1000));
            				} catch (InterruptedException e) {}
            				System.out.println ("Thread B have made " + withdrawals + " withdrawals and see the balance as " + balance);
        				}
    			}
		});
		A.start();
		B.start();
	}
}