#include <string>

class Base
{
public:
    Base(int dist);
    virtual ~Base() = default;
  
    int get_distance();
    virtual std::string get_color() = 0;
  
    // int increase_strength(); // Specific and only relevant for A
    // int increase_volume(); // Specific and only relevant for B
  
protected:
    int distance; // In both A and B
  
    // std::string color; // Not here, only in A
    // double strength; // Not here, only in A
    // double volume; // Not here, only in B
};