class Shape
{
	public:
		virtual int area() const = 0;
		virtual ~Shape();
};

class Square : public Shape
{
		int side;
		
	public:
		Square(int);
		virtual int area() const;
		int get_side() const;
};

class Rectangle : public Shape
{
		int width, height;
		
	public:
		Rectangle(int, int);
		virtual int area() const;
		int get_width() const;
		int get_height() const;
};