#include <iostream>
using namespace std;

class Animal {
  public:
    virtual void sound() {
      cout << "Some generic animal sound\n";
    }
};

class Cat : public Animal {
  public:
    void sound() override {
      cout << "Meow\n";
    }
};

class Cow : public Animal {
  public:
    void sound() override {
      cout << "Moo\n";
    }
};

int main() {
  Cat c;
  Cow w;
  c.sound();   // Meow
  w.sound();   // Moo
  return 0;
}