// Soln 9_3.cpp
  include <iostream>
  using std::cout;
  using std::endl;
  
  class CBase
  {
  protected:
     int m_anInt;
  public:
     CBase(int n) : m_anInt(n) { cout << "Base constructor" << endl; }
     virtual void Print() = 0;
  };
  
  class CDerived : public CBase
  {
  public:
     CDerived(int n) : CBase(n) { cout << "Derived constructor" << endl; }
     void Print() { cout << "value is " << m_anInt << endl; }
  };
  
  int main()
  {
     CDerived d(3);
  
     d.Print();
  
     return 0;
  }