func_code_string: #include <bits/stdc++.h>   using namespace std;   inline void prnt(bool ok) { cout << (ok ?  YES  :  NO ); }   const int ppr = 257;   const long long INF = 2e18;   const int inf = 2e9;   const int mod = 1e9 + 7;   const int N = 1e6 + 123;   const long double pi = 3.141592653589793238462643;   const int dx[] = {1, 0, -1, 0};   const int dy[] = {0, 1, 0, -1};   int T, n, m;   bool u[N];   int main() {     ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);     cin >> T;     while (T--) {       cin >> n >> m;       for (int i = 1; i <= 3 * n; i++) u[i] = 0;       vector<int> cur;       for (int i = 1; i <= m; i++) {         int x, y;         cin >> x >> y;         if (u[x] || u[y]) continue;         u[x] = u[y] = 1;         cur.push_back(i);       }       if (cur.size() >= n) {         cout <<  Matching n ;         for (int i = 0; i < n; i++) cout << cur[i] <<    ;       } else {         cout <<  IndSet n ;         int cnt = 0;         for (int i = 1; i <= 3 * n; i++) {           if (cnt == n) break;           if (!u[i]) {             cnt++;             cout << i <<    ;           }         }       }       cout <<   n ;     }     return 0;   }   