#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <math.h>
#include <iomanip>
#include <limits>
#include <list>
#include <queue>
#include <tuple>
#include <map>
#include <stack>
#include <set>
#include <bitset>
#include <functional>
#include <cassert>
using namespace std;
#define fast_io ios_base::sync_with_stdio (false) ; cin.tie(0) ; cout.tie(0) ;
#define ll long long int
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define reps(i,n) for(int i=1; i<=(int)(n); i++)
#define REP(i,n) for(int i=n-1; i>=0; i--)
#define REPS(i,n) for(int i=n; i>0; i--)
#define MOD (long long int)(1e9+7)
#define INF (int)(1e9)
#define LINF (long long int)(1e18)
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
#define all(v) v.begin(), v.end()
typedef pair<int, int> Pii;
typedef pair<ll, ll> Pll;

ll mpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = mpow(a,b/2); return memo*memo%MOD;}
  else return mpow(a,b-1) * a % MOD;
}
ll lpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = lpow(a,b/2); return memo*memo;}
  else return lpow(a,b-1) * a;
}
ll gcd(ll a, ll b){
  if(b==0) return a;
  else return gcd(b, a%b);
}
vector<ll> kaijo_memo;
ll kaijo(ll n){
  if(kaijo_memo.size() > n) return kaijo_memo[n];
  if(kaijo_memo.size() == 0) kaijo_memo.push_back(1);
  while(kaijo_memo.size() <= n) kaijo_memo.push_back(kaijo_memo[kaijo_memo.size()-1] * kaijo_memo.size() % MOD);
  return kaijo_memo[n];
}
vector<ll> gyaku_kaijo_memo;
ll gyaku_kaijo(ll n){
  if(gyaku_kaijo_memo.size() > n) return gyaku_kaijo_memo[n];
  if(gyaku_kaijo_memo.size() == 0) gyaku_kaijo_memo.push_back(1);
  while(gyaku_kaijo_memo.size() <= n) gyaku_kaijo_memo.push_back(gyaku_kaijo_memo[gyaku_kaijo_memo.size()-1] * mpow(gyaku_kaijo_memo.size(), MOD-2) % MOD);
  return gyaku_kaijo_memo[n];
}

ll nCr(ll n, ll r){
  if(n == r) return 1;//0個の丸と-1個の棒みたいな時に時に効く？不安.
  if(n < r || r < 0) return 0;
  ll ret = 1;
  if(n <= 1e7){
    ret *= kaijo(n); ret %= MOD;
    ret *= gyaku_kaijo(r); ret %= MOD;
    ret *= gyaku_kaijo(n-r); ret %= MOD;
  }else{
    rep(i,r){
      ret *= n-i; ret %= MOD;
      ret *= mpow(r-i, MOD-2); ret %= MOD;
    }
  }
  return ret;
}

/*std::mt19937 mt{ std::random_device{}() };

std::uniform_int_distribution<int> dist(1, 6);
dist(mt);

while(1){
	val;
	cout << val << endl;
	sol1 = solver1();
	sol2 = solver2();
	if(sol1==sol2){
	cout << "OK" << endl;
	}else{
	cout << "NG" << endl;
	cout << sol1 << endl;
	cout << sol2 << endl;
	break;
	}
}
*/

int main(void){
  fast_io
  cout<<fixed<<setprecision(15);
  int n,m;
  cin >> n >> m;
  vector<vector<int>> M(n);
  rep(i,m){
	  int a,b;
	  cin >> a >> b;
	  a--;
	  b--;
	  M[a].push_back(b);
	  M[b].push_back(a);
  }
  int ans = 0;
  vector<int> s(n,-1);
  rep(i,n){
	  //cout << "i " << i << endl;
	  if(s[i] != -1) continue;
	  int cnt = 0;
	  vector<int> st;
	  st.push_back(i);
	  s[i] = i;
	  while(1){
		  int p = st[0];
		  st.erase(st.begin());
		  cnt++;
		  //cout <<"cnt" << cnt << endl;
		  rep(j,M[p].size()){
			  if(s[M[p][j]] == -1){
				  st.push_back(M[p][j]);
			  }
			  s[M[p][j]] = i;
		  }
		  if(st.size() == 0) break;
		 // cout << p <<endl;

	  }
	  ans = max(ans,cnt);
  }
  cout << ans << endl;
  return 0;
}


Measured memory_bytes: 15692