#include <iostream>

class Base {
public:
  virtual ~Base() = default;
  virtual void print_num(int i = 1) {
    std::cout << "Base " << i << '\n';
  }
};

class Derived: public Base {
public:
  void print_num(int i = 2) override {
    std::cout << "Derived " << i << '\n';
  }
};

int main() {
  Derived derived;
  Base* base = &derived;
  derived.print_num(); // Prints "Derived 2"
  base->print_num(); // Prints "Derived 1"
}