class UseBetterStack {
    public static void main(String[ ] args) {
        System.out.println("Hello World!");
        BetterStack s = new BetterStack();
        try {
            Integer i = new Integer(27);  s.push(i);
            Integer j = new Integer(42);  s.push(j);
            Integer k = new Integer(69);  s.push(k);
            System.out.println(s.pop().toString());
            System.out.println(s.pop().toString());
            System.out.println(s.pop().toString());
            System.out.println(s.pop().toString());
        } 
        catch( BetterStackException e ) {
            System.out.println("empty stack");
        }  
    }
}