class Dog {
	protected String bark() {return "woof "; }
}
class Beagle extends Dog {
	private String bark() { return "arf "; }
}


class Test {
	public static void main(String args[]) {
		Dog[] dogs = {new Dog(), new Beagle()};
		for(Dog d : dogs)
			System.out.print(d.bark());
	}
}