#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define dbg(...) do{cerr<<__LINE__<<": ";dbgprint(#__VA_ARGS__, __VA_ARGS__);}while(0);

using namespace std;

namespace std{template<class S,class T>struct hash<pair<S,T>>{size_t operator()(const pair<S,T>&p)const{return ((size_t)1e9+7)*hash<S>()(p.first)+hash<T>()(p.second);}};template<class T>struct hash<vector<T>>{size_t operator()(const vector<T> &v)const{size_t h=0;for(auto i : v)h=h*((size_t)1e9+7)+hash<T>()(i)+1;return h;}};}
template<class T>ostream& operator<<(ostream &os, const vector<T> &v){os<<"[ ";rep(i,v.size())os<<v[i]<<(i==v.size()-1?" ]":", ");return os;}template<class T>ostream& operator<<(ostream &os,const set<T> &v){os<<"{ "; for(const auto &i:v)os<<i<<", ";return os<<"}";}
template<class T,class U>ostream& operator<<(ostream &os,const map<T,U> &v){os<<"{";for(const auto &i:v)os<<" "<<i.first<<": "<<i.second<<",";return os<<"}";}template<class T,class U>ostream& operator<<(ostream &os,const pair<T,U> &p){return os<<"("<<p.first<<", "<<p.second<<")";}
void dbgprint(const string &fmt){cerr<<endl;}template<class H,class... T>void dbgprint(const string &fmt,const H &h,const T&... r){cerr<<fmt.substr(0,fmt.find(","))<<"= "<<h<<" ";dbgprint(fmt.substr(fmt.find(",")+1),r...);}
typedef long long ll;typedef vector<int> vi;typedef pair<int,int> pi;const int inf = (int)1e9;const double INF = 1e12, EPS = 1e-9;
void visit(const vector<vi> & g, int v, int u,
    vector< vector<int> >& tecomp,
    stack<int>& roots, stack<int>& S, vector<bool>& inS,
    vector<int>& num, int& time) {
  num[v] = ++time;
  S.push(v); inS[v] = true;
  roots.push(v);
  for(int w : g[v]) {
    if (num[w] == 0)
      visit(g, w, v, tecomp, roots, S, inS, num, time);
    else if (u != w && inS[w])
      while (roots.size() && num[roots.top()] > num[w]) roots.pop();
  }
  if (v == roots.top()) {
    tecomp.push_back(vector<int>());
    while (S.size()) {
      int w = S.top(); S.pop(); inS[w] = false;
      tecomp.back().push_back(w);
      if (v == w) break;
    }
    roots.pop();
  }
}
vector<vi> calc_te(const vector<vi>& g) {
  const int n = g.size();
  vector<int> num(n);
  vector<bool> inS(n);
	vector<vi> tecomp;
  stack<int> roots, S;
  int time = 0;
  rep(u, n) if (num[u] == 0) {
    visit(g, u, n, tecomp, roots, S, inS, num, time);
  }
	return tecomp;
}
int main(){
	cin.tie(0); cin.sync_with_stdio(0);
	vector<vi> e, te;
	{
		int n, m; cin >> n >> m;
		vector<vi> g(n);
		rep(i, m){
			int s, t; cin >> s >> t;
			g[s].pb(t);
			g[t].pb(s);
		}
		te = calc_te(g);
		vi to(n, -1);
		rep(i, te.size()) for(int j : te[i]) to[j] = i;
		
		e.resize(te.size());
		rep(i, n) for(int j : g[i]) if(to[i] != to[j]) e[to[i]].pb(to[j]);
	}
	//dbg(te); rep(i, te.size()) dbg(e[i]);
	
	vector<vi> sum(2, vi(e.size(), -1));
	function<void(int,int,int)> rec = [&](int c, int p, int u){
		int &res = sum[u][c];
		if(res >= 0) return;
		res = 0;
		
		for(int i : e[c]) if(i != p){
			rep(j, 2) rec(i, c, j);
			if(u) res += sum[0][i];
			else res += max(sum[0][i], sum[1][i]);
		}
		if(u) res += te[c].size();
	};
	int ans = 0;
	rep(i, e.size()) if(sum[0][i] < 0){
		rep(j, 2) rec(i, i, j);
		ans += max(sum[0][i], sum[1][i]);
	}
	cout << ans << endl;
	
	return 0;
}


Measured memory_bytes: 19740