func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 4e5 + 100;   vector<int> vec[maxn];   int n, m, k;   int d[maxn], cnt;   bool vis[maxn];   void dfs(int x) {     vis[x] = 1;     d[++cnt] = x;     for (int i = 0; i < vec[x].size(); i++) {       if (vis[vec[x][i]]) continue;       dfs(vec[x][i]);       d[++cnt] = x;     }   }   int main() {     scanf( %d%d%d , &n, &m, &k);     for (int i = 1; i <= m; i++) {       int u, v;       scanf( %d%d , &u, &v);       vec[u].push_back(v);       vec[v].push_back(u);     }     dfs(1);     int x = (2 * n + k - 1) / k;     for (int i = 1; i <= k; i++) {       int c = min(x, cnt);       if (c == 0) {         cout <<  1 1  << endl;         continue;       }       cout << c <<    ;       for (int i = 1; i <= c && cnt != 0; i++, cnt--) {         cout << d[cnt] <<    ;       }       cout << endl;     }     return 0;   }   