class BaseFrequentFlyer {
  // Associations
  // Attributes
  private:
    string name;
    int number;
    int miles;
  // Operations
  public:
    BaseFrequentFlyer(string name, int number, int miles);  
    virtual ~BaseFrequentFlyer();
    void addMiles ( int realMiles );
    virtual int realMilesToAirmiles ( int realMiles ) = 0;
    void printData (  );
};