func_code_string: #include <bits/stdc++.h>   using namespace std;   using i64 = long long;   void solve() {     int n, m, k;     cin >> n >> m >> k;     vector<unordered_set<int> > gr(n);     for (int i = 0; i < m; ++i) {       int a, b;       cin >> a >> b;       --a;       --b;       gr[a].insert(b);       gr[b].insert(a);     }     set<int> rem;     for (int i = 0; i < n; ++i) rem.insert(i);     map<int, set<int> > degs;     for (int i = 0; i < n; ++i) degs[gr[i].size()].insert(i);     while (true) {       if (rem.size() < k) {         cout << -1 << endl;         return;       }       if (degs.begin()->first >= k) {         cout << 1 <<     << rem.size() << endl;         for (int v : rem) cout << v + 1 <<    ;         cout << endl;         return;       }       int deg_to_remove = degs.begin()->first;       int to_remove = *degs.begin()->second.begin();       if (deg_to_remove == k - 1) {         bool clique = true;         vector<int> cand;         cand.push_back(to_remove);         for (int u : gr[to_remove]) cand.push_back(u);         for (int i = 0; clique && i < cand.size(); ++i)           for (int j = i + 1; j < cand.size(); ++j)             if (!gr[cand[i]].count(cand[j])) {               clique = false;               break;             }         if (clique) {           cout << 2 << endl;           for (int v : cand) cout << v + 1 <<    ;           cout << endl;           return;         }       }       rem.erase(to_remove);       for (int u : gr[to_remove]) {         int deg_u = gr[u].size();         degs[deg_u].erase(u);         if (degs[deg_u].empty()) degs.erase(deg_u);         degs[deg_u - 1].insert(u);         gr[u].erase(to_remove);       }       gr[to_remove].clear();       if (degs[deg_to_remove].size() == 1)         degs.erase(deg_to_remove);       else         degs[deg_to_remove].erase(to_remove);     }   }   int main() {     ios::sync_with_stdio(0);     int tc;     cin >> tc;     for (int t = 0; t < tc; ++t) solve();     return 0;   }   