public class PolymorphismExample {
  
  public static void main(String args[]) {
    MountainBike bike = new MountainBike(10,20,30,40);
    Bicycle bicycle = bike;
    
    System.out.println(bicycle);
    System.out.println("------");
    System.out.println(bike);
    
    bicycle = new Bicycle(15,25,35); 
    //bicycle = new MountainBike(15,25,35,45);
    
    if( bicycle instanceof MountainBike )
      bike = (MountainBike) bicycle;
    
    System.out.println("------");
    System.out.println(bike);
   
    System.out.println("------");
    RacingMountainBike rbike = new RacingMountainBike(10, 20, 30, 40, 100);
    
    bicycle = rbike;
    System.out.println(bicycle);
    
  }
  
}