func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 1;   bool v[N];   int n, m, x, y, k, q[N], t, d[N], A[N], c;   vector<int> a[N];   void D(int x) {     q[++t] = x, d[x] = t;     for (int i = 0; i < a[x].size(); i++)       if (!d[a[x][i]])         D(a[x][i]);       else if (d[x] - d[a[x][i]] + 1 >= k) {         cout << 2 <<   n  << d[x] - d[a[x][i]] + 1 <<   n ;         for (int j = d[a[x][i]]; j <= d[x]; j++) cout << q[j] <<    ;         exit(0);       }     if (!v[x]) {       A[++c] = x;       for (int i = 0; i < a[x].size(); i++) v[a[x][i]] = true;     }     t--;   }   int main() {     cin >> n >> m;     while (m-- && cin >> x >> y) a[x].push_back(y), a[y].push_back(x);     k = sqrt(n - 1) + 1, D(1);     cout << 1 <<   n ;     for (int i = 1; i <= k; i++) cout << A[i] <<    ;     return 0;   }   