#include <iostream.h>

class C;

class A
{
  public:
    A() { f(); }
    virtual void DO() { cout << "A::DO()\n"; }
  private:
   virtual void f() { cout << "A::f()\n"; }
   void test() { cout << "A::test()\n"; }
   friend class C;
};

class B : public A
{
  private:
   virtual void DO() { cout << "B::DO()\n"; }
   virtual void f() { cout << "B::f()\n"; }
};

class C
{
  public:
    C(B *b) : m_pB(b) { m_pB->test(); }
  private:
    B* m_pB;
};

void main()
{
(1)  B *b = new B;
     A *a = b;
(2)  a->DO();
(3)  C c(b);

     delete b;
}