#ifndef z
#define z
class shapes{
protected: 
	int area;
public:
	shapes():area(-1){}
	void setArea(const int x){
		area = x;
	}
	int getArea()const{
		return area;
	}

	// if used, no polymorphism:
	//void print(){cout << "shapes print"<< endl;}

	// if used, base class can not be instantiated
    //virtual void print()=0;

	// if used, base class can be instantiated, polymophism works
	virtual void print(){cout << "non pure" << endl;}
};
#endif