#include <iostream>
using namespace std;
class Mammal
{
public:
  Mammal( )
  {
    cout<<"Mammal constructor called."<<endl;
  }
  virtual ~Mammal()
  {
    cout<<"Mammal destructor called."<<endl;
  }
  virtual void Speak() const
  {
    cout<<"Mammal speak."<<endl;
  }
};

class Dog : public Mammal
{
public:
  Dog()
  {
    cout<<"Dog constructor called."<<endl;
  }
  ~Dog()
  {
    cout<<"Dog destructor called."<<endl;
  }
  void Speak() const
  {
    cout<<"Woof!"<<endl;
  }
};
int main()
{
  Mammal *p=new Dog;
  p->Speak();
  delete p;
  return 0;
}