[Ch15] New Ryan and Monica with synchronization. Except.. it doesn't stop the problem

package ch15;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

public class RyanAndMonicaSynchronizedTest {

  public static void main(String[] args) {

    BankAccount account = new BankAccount();

    RyanAndMonicaSynchronizedJob ryan = new RyanAndMonicaSynchronizedJob("Ryan", account);

    RyanAndMonicaSynchronizedJob monica = new RyanAndMonicaSynchronizedJob("Monica", account);

    ExecutorService executor = Executors.newFixedThreadPool(2);

    executor.execute(ryan);

    executor.execute(monica);

    executor.shutdown();

  }

}

class RyanAndMonicaSynchronizedJob implements Runnable {

  private final String name;

  private final BankAccount account;

  RyanAndMonicaSynchronizedJob(String name, BankAccount account) {

    this.name = name;

    this.account = account;

  }

  public void run() {

    for (int i = 0; i < 10; i++) {

      makeWithdrawal(10);

      if (account.getBalance() < 0) {

        System.out.println("Overdrawn!");

      }

    }

  }

  private synchronized void makeWithdrawal(int amount) {

    if (account.getBalance() >= amount) {

      System.out.println(name + " is about to withdraw");

      try {

        System.out.println(name + " is going to sleep");

        Thread.sleep(500);

      } catch (InterruptedException ex) {ex.printStackTrace();}

      System.out.println(name + " woke up.");

      account.withdraw(amount);

      System.out.println(name + " completes the withdrawal");

    } else {

      System.out.println("Sorry, not enough for " + name);

    }

  }

}