func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     int n;     cin >> n;     vector<pair<int, bool>> v(2 * n);     for (int i = 0; i < 2 * n; i++) cin >> v[i].first, v[i].second = true;     long long ans = 0, cc = 0;     for (int i = 0; i < 2 * n; i++) {       if (!v[i].second) continue;       cc = 0;       v[i].second = false;       for (int j = i + 1; j < 2 * n; j++) {         if (v[j].second && v[i].first != v[j].first) {           cc++;         } else if (v[i].first == v[j].first) {           v[j].second = false;           break;         }       }       ans += cc;     }     cout << ans;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     int chill = 1;     while (chill--) {       solve();     }   }   