text: #pragma once
  #include <iostream>
  //using namespace std;
  
  class Element {
  public:
  	Element();
  	~Element();
  	virtual double getX() const;
  	virtual double getY() const;
  	virtual double getZ() const;
  	virtual void menu();
  	virtual std::istream& extractor(std::istream& i);
  	virtual std::ostream& inserter(std::ostream& o) const;
  };
  
  std::istream& operator>>(std::istream& i, Element& el);
  std::ostream& operator<<(std::ostream& o, const Element& el);
  