#include <iostream>
#include <cmath>
using namespace std;

class Point
{
  double x;
  double y;
public:
  Point();
  Point(double, double);
  double distance(const Point &b);
};

Point::Point()
{
  x=y=0;
}

Point::Point(double a, double b)
{
  x=a;
  y=b;
}

double Point::distance(const Point &b)
{
  return sqrt (((x-b.x)*(x-b.x)) + ((y-b.y)*(y-b.y)));
}

int main()
{
  Point a;
  Point b(3, 4);

  cout << "Distance between point a and b is " << a.distance(b) << endl;
}