#include <iostream>
  
class Mammal
{
public:
    Mammal():age(1) { std::cout << "Mammal constructor ...\n"; }
    ~Mammal() { std::cout << "Mammal destructor ...\n"; }
    void move() const { std::cout << "Mammal, move one step\n"; }
    virtual void speak() const { std::cout << "Mammal speak!\n"; }
  
protected:
    int age;
};
  
class Dog : public Mammal
{
public:
    Dog() { std::cout << "Dog constructor ...\n"; }
    ~Dog() { std::cout << "Dog destructor ..\n"; }
    void wagTail() { std::cout << "Wagging tail ...\n"; }
    void speak() const { std::cout << "Woof!\n"; }
    void move() const { std::cout << "Dog moves 5 steps ...\n"; }
};
  
int main()
{
    Mammal *pDog = new Dog;
    pDog->move();
    pDog->speak();
    return 0;
}