func_code_string: #include <bits/stdc++.h>   using namespace std;   const int Maxn = 100005;   const int Maxm = 500;   int T;   int n, m, k;   vector<int> un;   int my[Maxn];   bool has[Maxm][Maxm];   set<int> neigh[Maxn];   void Solve(priority_queue<pair<int, int> > &Q) {     bool assigned = false;     int inside = n;     while (!Q.empty() && -Q.top().first < k) {       int v = Q.top().second, d = -Q.top().first;       Q.pop();       if (neigh[v].size() != d) continue;       if (neigh[v].size() == k - 1) {         if (!assigned && inside < Maxm) {           int pnt = 0;           for (int i = 1; i <= n; i++)             if (!neigh[i].empty()) my[i] = pnt++;           for (int i = 0; i < pnt; i++) fill(has[i], has[i] + pnt, false);           for (int i = 1; i <= n; i++)             for (auto u : neigh[i]) has[my[i]][my[u]] = true;           assigned = true;         }         vector<int> seq;         for (auto u : neigh[v]) seq.push_back(u);         bool ok = true;         for (int i = 0; i < seq.size() && ok; i++)           for (int j = i + 1; j < seq.size() && ok; j++)             if (assigned)               ok = has[my[seq[i]]][my[seq[j]]];             else               ok = neigh[seq[i]].find(seq[j]) != neigh[seq[i]].end();         if (ok) {           printf( 2 n );           printf( %d , v);           for (int i = 0; i < seq.size(); i++) printf(  %d , seq[i]);           printf(  n );           return;         }       }       for (auto u : neigh[v]) {         neigh[u].erase(v);         if (assigned) has[my[v]][my[u]] = has[my[u]][my[v]] = false;         Q.push(pair<int, int>(-int(neigh[u].size()), u));       }       neigh[v].clear();       inside--;     }     vector<int> seq;     while (!Q.empty()) {       int v = Q.top().second, d = -Q.top().first;       Q.pop();       if (neigh[v].size() != d) continue;       seq.push_back(v);     }     if (seq.empty())       printf( -1 n );     else {       printf( 1 %d n , int(seq.size()));       for (int i = 0; i < seq.size(); i++)         printf( %d%c , seq[i], i + 1 < seq.size() ?     :   n );     }   }   int main() {     scanf( %d , &T);     while (T--) {       scanf( %d %d %d , &n, &m, &k);       for (int i = 1; i <= n; i++) neigh[i].clear();       for (int i = 0; i < m; i++) {         int a, b;         scanf( %d %d , &a, &b);         neigh[a].insert(b);         neigh[b].insert(a);       }       priority_queue<pair<int, int> > Q;       for (int i = 1; i <= n; i++)         Q.push(pair<int, int>(-int(neigh[i].size()), i));       Solve(Q);     }     return 0;   }   