func_code_string: #include <bits/stdc++.h>   int main(int argc, char const *argv[]) {     int T;     scanf( %d , &T);     while (T--) {       int n, m;       scanf( %d%d , &n, &m);       std::vector<short> vertices(3 * n, 0);       std::vector<int> edges;       for (int i = 0; i < m; i++) {         int u, v;         scanf( %d%d , &u, &v);         if (!vertices[u - 1] && !vertices[v - 1]) {           vertices[u - 1] = 1;           vertices[v - 1] = 1;           edges.push_back(i + 1);         }       }       if (edges.size() >= n) {         printf( Matching n );         for (int i = 0; i < n; i++) printf( %d n , edges[i]);       } else {         printf( IndSet n );         for (int i = 0, cnt = 0; i < 3 * n && cnt < n; i++) {           if (!vertices[i]) {             cnt++;             printf( %d n , i + 1);           }         }       }     }     return 0;   }   