public class MyClass {
public static void main(String[] args) {
B b = new C();
A a = b;
if (a instanceof A) System.out.println("A");
if (a instanceof B) System.out.println("B");
if (a instanceof C) System.out.println("C");
if (a instanceof D) System.out.println("D");
}
}
class A {}
class B extends A {}
class C extends B {}
class D extends C {}