func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, i, j;     cin >> n;     vector<pair<int, int>> v;     for (i = 0; i < n; i++) {       int x, y;       cin >> x >> y;       v.push_back(make_pair(x, y));     }     int ans = 0;     int total = 0;     bool u, d, l, r;     for (i = 0; i < n; i++) {       for (j = 0; j < n; j++) {         if (v[i].first > v[j].first && v[i].second == v[j].second) d = true;         if (v[i].first < v[j].first && v[i].second == v[j].second) u = true;         if (v[i].second > v[j].second && v[i].first == v[j].first) l = true;         if (v[i].second < v[j].second && v[i].first == v[j].first) r = true;       }       if (d && u && l && r) total++;       d = false;       u = false;       l = false;       r = false;     }     cout << total;   }   