interface WheelFittingExpert {

    String getDescription();
}

class CarExpert implements WheelFittingExpert {

    public String getDescription() {
        return "I can only fit car wheels";
    }
}

class BikeExpert implements WheelFittingExpert {

    public String getDescription()
    {
        return "I can only fit bike wheels";
    }
}