// CANONICAL
#include <iostream>
#include <array>
#include <vector>
#include <cassert>
using namespace std;

struct UnionFind {
	vector<int> par, rank, size; int c;
	UnionFind(int n) : par(n), rank(n,0), size(n,1), c(n) {
		for (int i = 0; i < n; ++i) par[i] = i;
	}
	int find(int i) { return (par[i] == i ? i : (par[i] = find(par[i]))); }
	bool same(int i, int j) { return find(i) == find(j); }
	int get_size(int i) { return size[find(i)]; }
	int count() { return c; }
	int merge(int i, int j) {
		if ((i = find(i)) == (j = find(j))) return -1; else --c;
		if (rank[i] > rank[j]) swap(i, j);
		par[i] = j; size[j] += size[i];
		if (rank[i] == rank[j]) rank[j]++;
		return j;
	}
};

pair<int, int> dfs(int u, int p, const vector<vector<int>> &g, const vector<bool>& off){
	int f = 0, t = 1;
	for(auto v : g[u]){
		if(v == p) continue;
		auto [f2, t2] = dfs(v, u, g, off);
		f += t2;
		t += f2;
	}

	if(off[u]) t = f;
	else t = max(t, f);
	return {f, t};
}

int main(){
	int n, m; cin >> n >> m;
	int k = m - n + 1;

	vector<vector<int>> g(n);
	UnionFind uf(n);
	vector<array<int, 2>> special;
	for(int i = 0; i < m; ++i){
		int u, v; cin >> u >> v;
		--u, --v;
		if(uf.same(u, v))
			special.push_back({u, v});
		else{
			g[u].push_back(v);
			g[v].push_back(u);
			uf.merge(u, v);
		}
	}

	assert(special.size() == k);

	int ans = 0;
	for(size_t m = 0; m < (1<<k); ++m){
		vector<bool> off(n, false);
		for(int i = 0; i < k; ++i) off[special[i][(m>>i)&1]] = true;
		ans = max(ans, dfs(0, -1, g, off).second);
	}
	cout << ans << endl;
}