func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long n, res = 0, a, b;     cin >> n;     vector<pair<long long, long long>> nums;     for (int i = 0; i < n; i++) {       cin >> a >> b;       nums.push_back({a, b});     }     for (int i = 0; i < n; i++) {       bool l = false, r = false, u = false, d = false;       for (int j = 0; j < n; j++)         if (i != j) {           if (nums[j].second == nums[i].second && nums[j].first > nums[i].first)             r = true;           if (nums[j].second == nums[i].second && nums[j].first < nums[i].first)             l = true;           if (nums[j].second > nums[i].second && nums[j].first == nums[i].first)             u = true;           if (nums[j].second < nums[i].second && nums[j].first == nums[i].first)             d = true;         }       res += (bool)(l && r && u && d);     }     cout << res;     return 0;   }   