class  Alarm  {
 public:
         void  turn_on()  {
                 std::cout  <<  "Alarm  on\n";
         }
 };

 class  BuzzerAlarm  :  public  Alarm  {
 public:
         void  turn_on()  {
                 std::cout  <<  "Buzzer  on\n";
         }
 };