func_code_string: #include <bits/stdc++.h>   using namespace std;   struct Vec2 {     int x, y;     bool left, right, top, bottom;     Vec2() : x(0), y(0), left(false), right(false), top(false), bottom(false) {}   };   int main() {     int n;     Vec2 points[200];     int ans = 0;     cin >> n;     for (int i = 0; i < n; ++i) cin >> points[i].x >> points[i].y;     for (int i = 0; i < n; ++i)       for (int j = 0; j < n; ++j) {         if (points[i].x > points[j].x && points[i].y == points[j].y)           points[j].right = true;         if (points[i].x < points[j].x && points[i].y == points[j].y)           points[j].left = true;         if (points[i].y < points[j].y && points[i].x == points[j].x)           points[j].bottom = true;         if (points[i].y > points[j].y && points[i].x == points[j].x)           points[j].top = true;       }     for (int i = 0; i < n; ++i)       if (points[i].left && points[i].right && points[i].top && points[i].bottom)         ans += 1;     cout << ans;     return 0;   }   