#include <iostream>

class point {
public:
    point(int x, int y)
        : x_ { x }
        , y_ { y } {};
    friend point operator+(point const& lhs,
        point const& rhs);
    friend std::ostream& operator<<(std::ostream& os,
        point const& p);

private:
    int x_;
    int y_;
};

point operator+(point const& lhs, point const& rhs)
{
    return point(lhs.x_ + rhs.x_, lhs.y_ + rhs.y_);
}

std::ostream& operator<<(std::ostream& os, point const& p)
{
    os << "(" << p.x_ << "," << p.y_ << ")";
    return os;
}

auto main() -> int
{
    point p1 { 1, 2 };
    point p2 { 2, 3 };
    std::cout << p1 + p2 << "\n";
}