// Slower C++ solution:
#define _USE_MATH_DEFINES

#include <iostream>

#include <sstream>

#include <string>

#include <list>

#include <vector>

#include <queue>

#include <algorithm>

#include <climits>

#include <cstring>

#include <cmath>

#include <stack>

#include <iomanip>

#include <tuple>

#include <functional>

#include <cfloat>

#include <map>

#include <set>

#include <array>

#include <stdio.h>

#include <string.h>

#include <random>

using ll = long long;

using ull = unsigned long long;

using namespace std;

#define int long long

#define CONTAINS_VEC(v,n) (find((v).begin(), (v).end(), (n)) != (v).end())

#define SORT(v) sort((v).begin(), (v).end())

#define RSORT(v) sort((v).rbegin(), (v).rend())

#define ARY_SORT(a, size) sort((a), (a)+(size))

#define REMOVE(v,a) (v.erase(remove((v).begin(), (v).end(), (a)), (v).end()))

#define REVERSE(v) (reverse((v).begin(), (v).end()))

#define ARY_REVERSE(v,a) (reverse((v), (v)+(a)))

#define REP(i, n) for (int (i)=0; (i) < (n); (i)++)

#define CONTAINS_MAP(m, a) (m).find((a)) != m.end()

#define CONTAINS_SET(m, a) (m).find((a)) != m.end()

void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }

void YESNO(bool b) { cout << (b ? "YES" : "NO") << endl; }





int N, M;

vector<int> _link[200001];

bool flg[200001];



signed main()

{

	cin >> N >> M;

	REP(i, M)

	{

		int a, b;

		cin >> a >> b;

		_link[a].push_back(b);

		_link[b].push_back(a);

	}





	int ma = 0;



	for (int i = 1; i <= N; i++)

	{

		int cnt = 1;

		if (flg[i]) continue;



		queue<int> q;

		q.push(i);

		

		while (q.size() > 0)

		{

			int n = q.front();

			q.pop();



			flg[n] = true;



			for (int l : _link[n])

			{

				if (!flg[l])

				{

					flg[l] = true;

					q.push(l);

					cnt++;

				}

			}

		}



		ma = max(ma, cnt);

	}



	cout << ma << endl;

}




// Faster C++ solution for the same problem (measured speedup: 6.423467802706206x):
#define _USE_MATH_DEFINES

#include <iostream>

#include <sstream>

#include <string>

#include <list>

#include <vector>

#include <queue>

#include <algorithm>

#include <climits>

#include <cstring>

#include <cmath>

#include <stack>

#include <iomanip>

#include <tuple>

#include <functional>

#include <cfloat>

#include <map>

#include <set>

#include <array>

#include <stdio.h>

#include <string.h>

#include <random>

using ll = long long;

using ull = unsigned long long;

using namespace std;

#define int long long

#define CONTAINS_VEC(v,n) (find((v).begin(), (v).end(), (n)) != (v).end())

#define SORT(v) sort((v).begin(), (v).end())

#define RSORT(v) sort((v).rbegin(), (v).rend())

#define ARY_SORT(a, size) sort((a), (a)+(size))

#define REMOVE(v,a) (v.erase(remove((v).begin(), (v).end(), (a)), (v).end()))

#define REVERSE(v) (reverse((v).begin(), (v).end()))

#define ARY_REVERSE(v,a) (reverse((v), (v)+(a)))

#define REP(i, n) for (int (i)=0; (i) < (n); (i)++)

#define REPE(i, n) for (int (i)=0; (i) <= (n); (i)++)

#define CONTAINS_MAP(m, a) ((m).find((a)) != m.end())

#define CONTAINS_SET(m, a) ((m).find((a)) != m.end())

void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }

void Yes() { cout << "Yes" << endl; }

void No() { cout << "No" << endl; }





struct UnionFind {

	vector<int> d;

	UnionFind(int n = 0) : d(n, -1) {}

	int find(int x) {

		if (d[x] < 0) return x;

		return d[x] = find(d[x]);

	}

	bool unite(int x, int y) {

		x = find(x); y = find(y);

		if (x == y) return false;

		if (d[x] > d[y]) swap(x, y);

		d[x] += d[y];

		d[y] = x;

		return true;

	}

	bool same(int x, int y) { return find(x) == find(y); }

	int size(int x) { return -d[find(x)]; }

};





signed main()

{

	int N, M;

	cin >> N >> M;



	UnionFind uf(N);



	REP(i, M)

	{

		int a, b;

		cin >> a >> b;

		a--;b--;

		uf.unite(a, b);

	}



	int ans = 0;

	REP(i, N)

	{

		ans = max(ans, uf.size(i));

	}

	cout << ans << endl;

}