enum ShapeType {circle, square};

interface IShape {
    const static ShapeType shapeType;
    void Draw();
}

class Circle implements IShape {
    const static ShapeType SHAPE_TYPE = ShapeType.circle;
    public Circle(int radius, Point center) {
        this.radius = radius;
        this.center = center;
    }
    public Draw() {
        /* 描く処理 */
    }
}

class Square implements IShape {
    const static ShapeType SHAPE_TYPE = ShapeType.square;
    public Square(int side, Point topLeft) {
        this.side    = side;
        this.topLeft = topLeft;
    }
    public Draw() {
        /* 描く処理 */
    }
}


class BigCircle extends Circle {}
class BigSquare extends Square {}