class Vehicle
   int fuel
   void Vehicule()
    fuel = 100
   return
/class

class Car is Vehicle
   int passengers
   void Car()
    passengers = 3
    fuel = 50
   return
/class

class Buggy is Car
  void Buggy()
    passengers = 2
    fuel = 50
  return
/class

Buggy mycar

print mycar.passengers