class A {}
class B extends A {}
class C extends A {}
class D extends C {}



class TrueOrFalse {
    public static void main(String[] args) {
        A a = new A();
        B b = new B();
        C c = new C();
        D d = new D();
        A e = new D();
        A f = new B();
        // System.out.println("a) " + (b instanceof A));
        // System.out.println("b) " + (c instanceof D));
        // System.out.println("c) " + (d instanceof A));
        // System.out.println("d) " + (e instanceof C));
        // System.out.println("e) " + (f instanceof C));


        B ab = (B) a;

        // if ( e instanceof B ) {
        //     B eb = (B) e;
        // }

        // D ed = (D) e;

        // if ( e instanceof D ) {
        //     D ed = (D) e;
        // }

        // B fb = (B) f;

        // C ec = (C) e;
    }
}