func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     long long n, m, i, j;     cin >> n >> m;     int x, y;     vector<vector<int> > adj(n);     vector<int> ncon(n, 0);     for (i = (0); i < (m); i++) {       cin >> x >> y;       adj[x - 1].push_back(y - 1);       adj[y - 1].push_back(x - 1);       ncon[x - 1]++;       ncon[y - 1]++;     }     vector<int> onecon;     for (i = (0); i < (n); i++)       if (ncon[i] == 1) onecon.push_back(i);     int maxd = 0;     queue<int> q;     vector<int> dist(n, 0), rem(n, 0);     for (auto i : onecon) {       q.push(i);       dist[i] = 1;     }     if ((int)((onecon).size()) != 0) maxd = 1;     while (!q.empty()) {       int cur = q.front();       q.pop();       rem[cur] = 1;       if (ncon[cur] == 1) maxd = max(maxd, dist[cur]);       for (auto next : adj[cur]) {         if (rem[next] == 1) continue;         ncon[next]--;         if (ncon[next] == 1) {           dist[next] = dist[cur] + 1;           q.push(next);         }       }     }     cout << maxd <<   n ;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     solve();     return 0;   }   