class Sfera {
	double x,y,z,r;
public:
	void sastavi ( double xx,double yy,double zz,double rr ){
		x=xx; y=yy; z=zz; r=rr; }
	double uzmiX () {return x;}
	double uzmiY () {return y;}
	double uzmiZ () {return z;}
	double uzmiR () {return r;}

	friend Sfera citaj ();
	friend void pisi (Sfera);
	double P() const;
	double V() const;
	double udaljenost() const;
};
