#include < iostream.h > class A { public : A ( ) { cout << "class A" << endl ; } } ; class B : virtual public A { public : B ( ) {cout << "class B" << endl ; } } ; class C : virtual public A { public : C ( ) {cout << "class C" << endl ; } } ; class D : public B , public C { public : D ( ) {cout << "class D" << endl ; } } ; void main ( ) { D dd ; }