// Avoid race hazards demonstrated by the RaceHazard
        // and UnsafeAccount classes by using the synchronized
        // methods of SaferAccount and a synchronized statement
        // in SaferATM.

class AccountManipulationMain {
    public static void main(String[] args){
        // Access to this account is shared by the three threads.
        SaferAccount acc = new SaferAccount();

        // Make regular debits of the given amount.
        new Thread(new DirectDebit(acc)).start();
        // Make regular deposits into the account.
        new Thread(new Saver(acc)).start();
        // Allow the user to withdraw money.
        new Thread(new SaferATM(acc)).start();
    }
}