public class Circle {
    private double radius;

    public Circle(double radius){
        if(radius<0) this.radius=0;
        else this.radius=radius;
    }

    public double getRadius() {
        return radius;
    }

    public double getArea(){
        return (radius*radius*Math.PI);
    }
}


public class Cylinder extends Circle {
    private double height;

    public Cylinder(double radius, double height) {
        super(radius);
        if(height<0) this.height=0;
        else this.height = height;
    }

    public double getHeight() {
        return height;
    }

    public double getVolume() {
        return getArea()*getHeight();
    }

}