//  declaration for class My3Vector
//  My3Vector.h
//
class My3Vector {
 private:        // coordinates, hidden
  double x;
  double y;
  double z;
 public:  
  My3Vector();// The default constructor
  My3Vector(double c1, double c2, double c3);// Other constructor
  // methods:
  double Length();  //   get length of vector
  // access elements
  double X();
  double Y();
  double Z();
  My3Vector Add( My3Vector & p );  // add two vectors
  void Print( );  // output
};