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

// TYPEDEF
// ----------------------------------------
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> Pair;
typedef vector<ll> vll;
typedef vector<vector<ll>> Graph;
typedef vector<string> vs;
typedef vector<pair<ll, ll>> Pll;
typedef queue<ll> qll;

// REPEAT
// ----------------------------------------
#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define REPD(i,n) for(ll i=n-1;i>=0;i--)
#define REPA(i,a) for(ll i=0;i<(ll)(a.size());i++);
#define FOR(i,a,b) for(ll i=a;i<=(ll)(b);i++)
#define FORD(i,a,b) for(ll i=a;i>=(ll)(b);i--)
#define COUT(a) cout << (a) << endl;
#define ENDL(a) cout << endl;
#define COUTA(i,a) for(ll i=0;i<(ll)(a.size());i++) {cout << (a)[i] << " ";} cout << endl;

// UTIL
// ----------------------------------------
#define pb push_back
#define paired make_pair
#define ALL(a) (a).begin(),(a).end()
#define SORT(a) sort((a).begin(),(a).end())
#define RSORT(a) sort((a).rbegin(), (a).rend())

// DEBUG
// ----------------------------------------
#ifdef _DEBUG
#define debug(x) cout << "[debug] " << #x << ": " << x << endl
#else
#define debug(x)
#endif

template <typename T>
void debugV(const vector<T> v) {
#ifdef _DEBUG
  rep(i, v.size()) {
    cout << i << ":" << v[i] << " ";
  }
  cout << endl;
#else
  (void)v;
#endif
}

// BIT FLAG
// ----------------------------------------
const unsigned int BIT_FLAG_0 = (1 << 0); // 0000 0000 0000 0001
const unsigned int BIT_FLAG_1 = (1 << 1); // 0000 0000 0000 0010
const unsigned int BIT_FLAG_2 = (1 << 2); // 0000 0000 0000 0100
const unsigned int BIT_FLAG_3 = (1 << 3); // 0000 0000 0000 1000
const unsigned int BIT_FLAG_4 = (1 << 4); // 0000 0000 0001 0000
const unsigned int BIT_FLAG_5 = (1 << 5); // 0000 0000 0010 0000
const unsigned int BIT_FLAG_6 = (1 << 6); // 0000 0000 0100 0000
const unsigned int BIT_FLAG_7 = (1 << 7); // 0000 0000 1000 0000
const unsigned int BIT_FLAG_8 = (1 << 8); // 0000 0001 0000 0000
const unsigned int BIT_FLAG_9 = (1 << 9); // 0000 0010 0000 0000
const unsigned int BIT_FLAG_10 = (1 << 10); // 0000 0100 0000 0000
const unsigned int BIT_FLAG_11 = (1 << 11); // 0000 1000 0000 0000

// CONST
// ----------------------------------------
constexpr ll INF = 0x3f3f3f3f3f3f3f3f;
constexpr double PI=3.14159265358979323846; // or M_PI
constexpr int MOD = 1000000007;


void Main() {
    ll n, m;
    cin >> n >> m;
    Graph group(n);
    vll flag(n, -1);
    vll group_size(n, 0);

    ll group_index = 0;
    REP(i, m) {
      ll a, b;
      cin >> a >> b;
      a--;
      b--;
      if (flag[a] == -1 and flag[b] == -1) {
        flag[a] = group_index;
        flag[b] = group_index;
        group[group_index].push_back(a);
        group[group_index].push_back(b);
        group_size[group_index] = group_size[group_index] + 2;
        group_index++;
      }
      else if (flag[a] == -1) {
        ll index = flag[b];
        flag[a] = index;
        group[index].push_back(a);
        group_size[index] = group_size[index] + 1;
      }
      else if (flag[b] == -1) {
        ll index = flag[a];
        flag[b] = index;
        group[index].push_back(b);
        group_size[index] = group_size[index] + 1;
      }
      else if (flag[a] == flag[b]) {
        continue;
      }
      else if (flag[a] != flag[b]) {
        if (group[flag[a]].size() > group[flag[b]].size()) {
          ll index = flag[a];
          ll b_index = flag[b];
          REP(i, group[b_index].size()) {
            ll member = group[b_index][i];
            // COUT(member);
            flag[member] = index;
            // COUT(index);
            group[index].push_back(member);
            group_size[index] = group_size[index] + 1;
          }
          group[b_index].clear();
        }
        else {
            ll index = flag[b];
            ll a_index = flag[a];
            // COUTA(l, group[flag[a]]);
            
            REP(i, group[a_index].size()) {
              ll member = group[a_index][i];
              flag[member] = index;
              group[index].push_back(member);
              group_size[index] = group_size[index] + 1;
            }
            
            group[a_index].clear();
        }
      }
    }

    ll max_size = *max_element(group_size.begin(), group_size.end());
    if (max_size == 0) {
      max_size = 1;
    }
    COUT(max_size);
}

int main()
{
	cin.tie(0);
	ios_base::sync_with_stdio(false);
	cout << fixed << setprecision(15);
	Main();
}

/*

3 2
*/


Measured memory_bytes: 19104