class A {
	public void f() {
		System.out.println("Blah.");
	}
}

class B extends A {
	public void f() {
		super.f();
		System.out.println(this.getClass().getName());
	}
}

class C extends B {

}

public class D extends C {
	public static void main(String[] args) {
		new A().f();
		System.out.println();

		new B().f();
		System.out.println();

		new C().f();
		System.out.println();

		new D().f();
	}
}

/*
vertex01% java D
Blah.

Blah.
B

Blah.
C

Blah.
D
*/