#include<bits/stdc++.h>
using namespace std;
struct point{
	int x,y;
	point(int x=0,int y=0):x(x),y(y) {}
};
point operator + (const point& A, const point& B){
	return point(A.x+B.x,A.y+B.y);
}
ostream& operator << (ostream&out, const point&p) {//刘汝佳的那本书上这里没怎么写清楚，前面一段还是能理解的
	out<<"("<<p.x<<","<<p.y<<")";
	return out;
}
int main()
{
	point a,b(1,2);
	a.x=3;
	cout<<a+b<<endl;
	return 0;
}