#include <algorithm>
#include <array>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
using namespace std;
typedef long long ll;
#define REP(i,n) for(ll i = 0; i < (ll)(n); ++i)
#define FOR(i,a,b) for(ll i = (a); i < (ll)(b); ++i)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(v) ((int)v.size())
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b; return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b; return true;
    }
    return false;
}
template<int MOD> struct Fp {
    ll val;
    constexpr Fp(ll v = 0) noexcept : val(v % MOD) {
        if (val < 0) val += MOD;
    }
    constexpr int getmod() { return MOD; }
    constexpr Fp operator - () const noexcept {
        return val ? MOD - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MOD) val -= MOD;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MOD;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        ll a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            ll t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % MOD;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, ll n) noexcept {
        if (n == 0) return 1;
        auto t = modpow(a, n / 2);
        t = t * t;
        if (n & 1) t = t * a;
        return t;
    }
};
constexpr ll MOD = 1e9 + 7;
using mint = Fp<MOD>;

#define pb push_back
#define mp make_pair
#define mt make_tuple

class UnionFind
{
public:
    UnionFind(){};
    ~UnionFind(){};
    void init(int num_entries) {
        num_entries_ = num_entries;
        par_.resize(num_entries_);
        rank_.resize(num_entries_, 0);
        member_num_.resize(num_entries_, 1);
        REP(i, num_entries_) {
            par_[i] = i;
        }
    }
    int find(int x) {
        if (par_[x] == x) return x;
        else return par_[x] = find(par_[x]);
    }
    void unite(int x, int y) {
        x = find(x); y = find(y);
        if (x == y) return;
        if (rank_[x] < rank_[y]) {
            par_[x] = y;
            member_num_[y] += member_num_[x];
            member_num_[x] = 0;
        } else {
            par_[y] = x;
            member_num_[x] += member_num_[y];
            member_num_[y] = 0;
            if (rank_[x] == rank_[y]) rank_[x]++;
        }
    }
    bool same(int x, int y) { return find(x) == find(y); }
    int size(int x) {
        return member_num_[this->find(x)];
    }
private:
    int num_entries_;
    std::vector<int> par_;
    std::vector<int> rank_;
    std::vector<int> member_num_;
};

int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int N, M;
    cin >> N >> M;
    UnionFind uf;
    uf.init(N);
    REP(m, M) {
        int a, b; cin >> a >> b; --a; --b;
        uf.unite(a, b);
    }
    int ans = 0;
    REP(n, N) {
        chmax(ans, uf.size(n));
    }
    cout << ans << endl;

    return 0;
}


Measured memory_bytes: 5552