class Cat : public Animal {
public:
   Cat () {
      printf("Creating a new \"Cat\".\n");
   }
   ~Cat ();
}

class Dog : public Animal {
public:
   Dog () {
      printf("Creating a new \"Dog\".\n");
   }
   ~Dog ();
}

class Snake : public Animal {
public:
   Snake () {
      printf("Creating a new \"Snake\".\n");
   }
   ~Snake ();
}