#include <iostream>

using namespace std;
class Point {
private:
    mutable int x;// we can change the value inside constant functions
    int y;
public:
    Point(int _x = 0, int _y = 0) {
        x = _x;
        y = _y;
    }
    Point(const Point &tmp) {
        x = tmp.x;
        y = tmp.y;
    }
     int get_x() const { // this means we cannot change any variable in the function
         x++; // since it's mutable, the value can be chagned even though it is a constant function
        return x;
    }
    int get_y() const {
        return y;
    }
};
int main()
{
    Point p(10, 20);
    cout << p.get_x() << endl;

    return 0;
}