#include <iostream.h>

class A { public: virtual void f(); };
class B: virtual public A { public: virtual void f(); };
class C: virtual public A { };
class D: public B, public C { };

main() {
    D d;
    A *ap = &d;
    ap->f();
}

void A::f() { cout << "A::f" << endl; }
void B::f() { cout << "B::f" << endl; }