func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long int n;     cin >> n;     vector<pair<int, int>> v;     for (int i = 0; i < n; i++) {       long long a, b;       cin >> a >> b;       v.push_back(make_pair(a, b));     }     int c = 0;     for (int i = 0; i < n; i++) {       int up = 0, lo = 0, r = 0, l = 0;       for (int j = 0; j < n; j++) {         if (v[i].first > v[j].first && v[i].second == v[j].second) up = 1;         if (v[i].first < v[j].first && v[i].second == v[j].second) lo = 1;         if (v[i].first == v[j].first && v[i].second < v[j].second) l = 1;         if (v[i].first == v[j].first && v[i].second > v[j].second) r = 1;       }       if (up + lo + l + r == 4) c++;     }     cout << c;   }   