func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t;     cin >> t;     while (t--) {       int kq = 0;       vector<pair<int, int> > res;       int n, k;       cin >> n >> k;       vector<bool> used(2 * n + 1, false);       for (int i = 1; i <= k; i++) {         int u, v;         cin >> u >> v;         res.push_back({min(u, v), max(u, v)});         used[u] = true;         used[v] = true;       }       vector<int> conlai;       for (int i = 1; i <= 2 * n; i++) {         if (!used[i]) conlai.push_back(i);       }       int len = n - k;       for (int i = 0; i < len; i++) {         res.push_back({conlai[i], conlai[i + len]});       }       for (int i = 0; i < res.size(); i++) {         for (int j = i + 1; j < res.size(); j++) {           int a = (res[j].first - res[i].first) * (res[j].second - res[i].first);           int b =               (res[j].first - res[i].second) * (res[j].second - res[i].second);           if (a * b < 0) {             kq++;           }         }       }       cout << kq << endl;     }   }   