// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
using namespace std::chrono;

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
	return '"' + s + '"';
}

string to_string(const char* s) {
	return to_string((string) s);
}

string to_string(bool b) {
	return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
	bool first = true;
	string res = "{";
	for (int i = 0; i < static_cast<int>(v.size()); i++) {
		if (!first) {
			res += ", ";
		}
		first = false;
		res += to_string(v[i]);
	}
	res += "}";
	return res;
}

template <size_t N>
string to_string(bitset<N> v) {
	string res = "";
	for (size_t i = 0; i < N; i++) {
		res += static_cast<char>('0' + v[i]);
	}
	return res;
}

template <typename A>
string to_string(A v) {
	bool first = true;
	string res = "{";
	for (const auto &x : v) {
		if (!first) {
			res += ", ";
		}
		first = false;
		res += to_string(x);
	}
	res += "}";
	return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
	return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
	return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
	return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

#define output cout

void debug_out() { output << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	output << " " << to_string(H);
	debug_out(T...);
}

#ifndef ONLINE_JUDGE
#define dbg(...) output << "[" << #__VA_ARGS__ << "] :", debug_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// functions: set.insert(val), *(set.find_by_order(order-1)), set.order_of_key(val)

#define ll long long
#define ull unsigned long long
#define FIO ios_base::sync_with_stdio(false);cin.tie(NULL);
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define ff first
#define ss second
#define vt vector
#define vll vt<ll>
#define pll pair<ll,ll>
#define vpll vt<pll>
#define vvll vt<vll>
#define all(v) v.begin(),v.end()
#define FOR(i,n) for(ll i=0;i<n;i++)
#define ffo(i,a,b) for(ll i=a;i<=b;i++)
#define rfo(i,a,b) for(ll i=a;i>=b;i--)
#define space cout<<"\n\n";
#define endl "\n"
#define pqmx priority_queue<ll>
#define pqmn priority_queue<ll,vll,greater<ll>>
#define fps(x,y) fixed<<setprecision(y)<<x
#define merg(a,b,c) set_union(a.begin(),a.end(),b.begin(),b.end(),inserter(c,c.begin()))
#define set_ar(arr,v) memset(arr,v,sizeof(arr))
#define go_t int testcases; cin>>testcases; ffo(caseno,1,testcases)

#define ctime auto start = high_resolution_clock::now()
#define etime auto stop = high_resolution_clock::now()
#define ptime auto z1z = duration_cast<microseconds>(stop-start); cout<<"Time elapsed : "<<z1z.count()<<" microseconds\n"

const ll mod = 1e9 + 7;
const ll N = 1e6 + 6;
const ll maxN = 2e5 + 5;
const ll MAX_SIZE = 2e6 + 6;
const ll INF = 0x3f3f3f3f3f3f3f3fll;
const double PI = 3.14159265359;

int dx[4] = { -1, 0, 1, 0};
int dy[4] = {0, 1, 0, -1};
// up, right, down, left

ll powerM(ll x, ll y, ll M = mod) { // default argument
	ll v = 1; x = x % M; while (y > 0) {if (y & 1)v = (v * x) % M; y = y >> 1; x = (x * x) % M;} return v;
}

ll power(ll x, ll y) {
	ll v = 1; while (y > 0) {if (y & 1)v = v * x; y = y >> 1; x = x * x;} return v;
}

ll n, m;
vll g[maxN];
int vis[maxN];

void dfs(ll node, ll& sz) {
	vis[node] = 1;
	++sz;
	for (auto& u : g[node]) {
		if (vis[u])
			continue;
		dfs(u, sz);
	}
}

int main()
{
#ifndef ONLINE_JUDGE
	freopen("in6.txt", "r", stdin);
	freopen("out2.txt", "w", stdout);
#endif
	FIO
	cin >> n >> m;
	map<ll, ll> hash;
	FOR(i, m) {
		ll a, b;
		cin >> a >> b;
		--a, --b;
		ll v = a * maxN + b;
		// this will be a unique id
		if (hash.find(v) != hash.end())
			continue;
		g[a].pb(b);
		g[b].pb(a);
	}
	ll ans = 0;
	ll cnt = 0;
	for (int i = 0; i < n; ++i) {
		if (vis[i]) {
			continue;
		}
		ll sz = 0;
		dfs(i, sz);
		ans = max(ans, sz);
		if (sz != 1)
			++cnt;
	}
	// if (cnt == 0)
	// 	cnt = 1;
	// ans = max(ans, cnt);
	cout << ans;
	return 0;
}


Measured memory_bytes: 24732