func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   using pii = pair<int, int>;   template <typename T>   using V = vector<T>;   const int N = 1e5 + 5;   bool taken[3 * N];   int main() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     int tc;     cin >> tc;     while (tc--) {       int n, m;       cin >> n >> m;       for (int i = 1; i <= 3 * n; ++i) taken[i] = false;       vector<pii> edges(m);       vector<int> matching;       for (auto &e : edges) {         cin >> e.first >> e.second;       }       int id = 0;       for (auto &e : edges) {         ++id;         if (taken[e.first] or taken[e.second]) continue;         matching.push_back(id);         taken[e.first] = taken[e.second] = true;       }       if ((int)matching.size() >= n) {         cout <<  Matching n ;         for (int i = 0; i < n; ++i) {           cout << matching[i] <<    ;         }       } else {         cout <<  IndSet n ;         for (int i = 1, cnt = 0; cnt < n; ++i) {           if (!taken[i]) {             cout << i <<    ;             ++cnt;           }         }       }       cout <<   n ;     }     return 0;   }   