NETMAX.cpp

#include <bits/stdc++.h>
using namespace std;

#define all(x) (x).begin(),(x).end()

const int N = 30005;

vector<int> adj[N];
int num[N], low[N];
int id = 0;
vector<int> s;
vector<vector<int>> res;

void chmin(int &a, int b) {
  if (a > b) a = b;
}

void dfs(int i, int p) {
  if (!adj[i].size()) {
    res.push_back({i});
    return;
  }
  num[i] = low[i] = ++id;
  for (auto& j : adj[i]) {
    if (num[j]) {
      chmin(low[i], num[j]);
    }
    else {
      s.push_back(i);
      dfs(j, i);
      chmin(low[i], low[j]);
      if (low[j] == num[i]) {
        vector<int> bicon;
        int u;
        do {
          u = s.back();
          s.pop_back();
          bicon.push_back(u);
        } while (u != i);
        res.push_back(bicon);
      }
    }
  }
  s.push_back(i);
}

signed main() {
  // freopen("in" , "r", stdin );
  cin.tie(0)->sync_with_stdio(0);
  int n, m; cin >> n >> m;
  for (int i = 1; i <= m; i++) {
    int u, v; cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  for (int i = 1; i <= n; i++) {
    if (!num[i]) dfs(i, -1);
  }
  // cout << res.size() << '\n';
  int ans = 0;
  for (auto& i : res) {
    sort(all(i));
    i.resize(unique(all(i)) - i.begin());
    // for (auto& j : i) cout << j << ' ';
    // cout << '\n';
    ans = max(ans, (int) i.size());
  }
  cout << ans << '\n';
}