func_code_string: #include <bits/stdc++.h>   using namespace std;   void File() {     freopen( output.txt ,  w , stdout);     freopen( input.txt ,  r , stdin);   }   void fast() {     ios::sync_with_stdio(NULL);     cout.tie(NULL);     cin.tie(NULL);   }   const double pi = 2 * acos(0.0);   const int nn = 5e2 + 5;   const int oo = 0x3f3f3f3f;   int main() {     fast();     int n, ans = 0;     pair<int, int> arr[nn];     cin >> n;     for (int i = 0; i < n; i++) cin >> arr[i].first >> arr[i].second;     for (int i = 0; i < n; i++) {       int cnt[4] = {};       for (int j = 0; j < n; j++) {         if (i == j) continue;         if (arr[i].first > arr[j].first && arr[i].second == arr[j].second)           cnt[0]++;         else if (arr[i].first < arr[j].first && arr[i].second == arr[j].second)           cnt[1]++;         else if (arr[i].first == arr[j].first && arr[i].second > arr[j].second)           cnt[2]++;         else if (arr[i].first == arr[j].first && arr[i].second < arr[j].second)           cnt[3]++;         if (cnt[0] && cnt[1] && cnt[2] && cnt[3]) {           ans++;           break;         }       }     }     cout << ans <<   n ;     return 0;   }   