#include <bits/stdc++.h>
using namespace std;
using LL = long long int;
#define incII(i, l, r) for(LL i = (l)    ; i <= (r); i++)
#define incID(i, l, r) for(LL i = (l)    ; i <  (r); i++)
#define incCI(i, l, r) for(LL i = (l) + 1; i <= (r); i++)
#define incCD(i, l, r) for(LL i = (l) + 1; i <  (r); i++)
#define decII(i, l, r) for(LL i = (r)    ; i >= (l); i--)
#define decID(i, l, r) for(LL i = (r) - 1; i >= (l); i--)
#define decCI(i, l, r) for(LL i = (r)    ; i >  (l); i--)
#define decCD(i, l, r) for(LL i = (r) - 1; i >  (l); i--)
#define inc(i, n)  incID(i, 0, n)
#define dec(i, n)  decID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec1(i, n) decII(i, 1, n)
auto inII = [](auto v, auto l, auto r) { return (l <= v && v <= r); };
auto inID = [](auto v, auto l, auto r) { return (l <= v && v <  r); };
auto inCI = [](auto v, auto l, auto r) { return (l <  v && v <= r); };
auto inCD = [](auto v, auto l, auto r) { return (l <  v && v <  r); };
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define MT make_tuple
#define FI first
#define SE second
#define FR front()
#define BA back()
#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
auto setmin   = [](auto & a, auto b) { return (b <  a ? a = b, true : false); };
auto setmax   = [](auto & a, auto b) { return (b >  a ? a = b, true : false); };
auto setmineq = [](auto & a, auto b) { return (b <= a ? a = b, true : false); };
auto setmaxeq = [](auto & a, auto b) { return (b >= a ? a = b, true : false); };
#define SC static_cast
#define SI(v) SC<int>(v.size())
#define SL(v) SC<LL >(v.size())
#define RF(e, v) for(auto & e: v)
#define until(e) while(! (e))
#define if_not(e) if(! (e))
#define ef else if
#define UR assert(false)
#define CT continue
#define RV(v) reverse(ALL(v))
auto * IS = & cin;
// input elements (as a tuple)
template<typename U, int I> void in_([[maybe_unused]] U & t) { }
template<typename U, int I, typename A, typename ... B> void in_(U & t) { (* IS) >> get<I>(t); in_<U, I + 1, B ...>(t); }
template<typename ... T> auto in() { tuple<T ...> t; in_<tuple<T ...>, 0, T ...>(t); return t; }
// input an array
template<typename T, int N> auto ain() { array<T, N> a; inc(i, N) { (* IS) >> a[i]; } return a; }
// input a (multi-dimensional) vector
template<typename T> T vin() { T v; (* IS) >> v; return v; }
template<typename T, typename N, typename ... M> auto vin(N n, M ... m) {
	vector<decltype(vin<T, M ...>(m ...))> v(n); inc(i, n) { v[i] = vin<T, M ...>(m ...); } return v;
}
// input multi-column (as a tuple of vector)
template<typename U, int I> void colin_([[maybe_unused]] U & t) { }
template<typename U, int I, typename A, typename ... B> void colin_(U & t) {
	A a; (* IS) >> a; get<I>(t).push_back(a); colin_<U, I + 1, B ...>(t);
}
template<typename ... T> auto colin(int n) {
	tuple<vector<T> ...> t; inc(i, n) { colin_<tuple<vector<T> ...>, 0, T ...>(t); } return t;
}
auto * OS = & cout;
// output elements
void out_([[maybe_unused]] string s) { }
template<typename A> void out_([[maybe_unused]] string s, A && a) { (* OS) << a; }
template<typename A, typename ... B> void out_(string s, A && a, B && ... b) { (* OS) << a << s; out_(s, b ...); }
auto outF = [](auto x, auto y, auto z, auto ... a) { (* OS) << x; out_(y, a ...); (* OS) << z << flush; };
auto out  = [](auto ... a) { outF("", " " , "\n", a ...); };
auto outS = [](auto ... a) { outF("", " " , " " , a ...); };
auto outL = [](auto ... a) { outF("", "\n", "\n", a ...); };
auto outN = [](auto ... a) { outF("", ""  , ""  , a ...); };
array<string, 3> SEQ_FMT = { "", " ", "" };
auto & SEQ_BEG = SEQ_FMT[0];
auto & SEQ_MID = SEQ_FMT[1];
auto & SEQ_END = SEQ_FMT[2];
// output a (multi-dimensional) vector
template<typename T> ostream & operator<<(ostream & os, vector<T> const & v) {
	os << SEQ_BEG; inc(i, SI(v)) { os << (i == 0 ? "" : SEQ_MID) << v[i]; } return (os << SEQ_END);
}
template<typename T> void vout_(T && v) { (* OS) << v; }
template<typename T, typename A, typename ... B> void vout_(T && v, A a, B ... b) {
	inc(i, SI(v)) { (* OS) << (i == 0 ? "" : a); vout_(v[i], b ...); }
}
template<typename T, typename A, typename ... B> void vout(T && v, A a, B ... b) {
	vout_(v, b ...); (* OS) << a << flush;
}

// ---- ----

class UnionFind {
private:
	int n, s;
	vector<int> t;
	vector<vector<int>> v;
public:
	UnionFind(int arg_n = 0) { init(arg_n); }
	void init(int arg_n) {
		n = s = arg_n;
		t.clear();
		v.clear();
		inc(i, n) { t.PB(i); v.EB(1, i); }
	}
	int get_n() { return n; }
	int size() { return s; }
	int id(int x) { return t.at(x); }
	const vector<vector<int>> & get_v() { return v; }
	bool unite(int x, int y) {
		x = id(x);
		y = id(y);
		if(x == y) { return false; }
		if(v[x].size() < v[y].size()) { swap(x, y); }
		for(auto & e: v[y]) { v[x].PB(e); t[e] = x; }
		v[y].clear();
		s--;
		return true;
	}
	bool same(int x, int y) { return (id(x) == id(y)); }
	const vector<int> & operator[](int x) { return v[id(x)]; }
	friend ostream & operator<<(ostream & os, const UnionFind & uf) {
		inc(i, uf.n) { os << i << ": "; for(auto & e: uf.v[i]) { os << e << " "; } os << "\n"; }
		return os;
	}
};

// ---- ----

int main() {
	auto [n, m] = in<int, int>();
	UnionFind uf(n);
	inc(i, m) {
		auto [a, b] = in<int, int>();
		a--; b--;
		uf.unite(a, b);
	}
	
	int ans = 0;
	inc(i, n) { setmax(ans, SI(uf[i])); }
	out(ans);
}


Measured memory_bytes: 18768