#include <fstream>
#include <algorithm>
#include <vector>
#include <deque>
using namespace std;

#define in "biconex.in"
#define out "biconex.out"
#define N 100005

ofstream fout (out);

vector <int> dfn (N, -1), low (N, -1), LIST[N];
vector <bool> A(N, 0);

struct muchie {
	int x, y;
};

int n, m, st = 1, nf, num, nr;

deque <muchie> S;

muchie init (int x, int y)
{
	muchie a;
	a.x = x, a.y = y;
	return a;
}

/*void Afis(int u, int x)
{
	nr++;
	do {
		fout << S[S.size() -1].x << " " << S[S.size() - 1].y << "\n";
		S.pop_back();
	} while (S[S.size() -1].x != u && S[S.size() -1].y != x);
}*/
 
void Biconex (int u, int tu)
{
	dfn[u] = low[u] = ++num;
	for (unsigned z = 0; z < LIST[u].size(); ++z) {
		int x = LIST[u][z];
		if (x != tu && dfn[x] < dfn[u]) {
			S.push_back (init (u, x));
		if (dfn[x] == -1) {
			if (u == st)
				nf++;
			Biconex (x, u);
			low[u] = min (low[u], low[x]);
			if (low[x] >= dfn[u]) {
				if (u != st) 
					A[u] = 1;
				nr++;
				//Afis(u, x);
			}
		}
		else
			if (x != tu)
				low[u] = min (low[u], dfn[x]);
		}
	}
}

int main ()
{
	ifstream fin (in);
	fin >> n >> m;
	for (int i = 0; i < m; ++i) {
		int x, y;
		fin >> x >> y;
		LIST[x].push_back (y);
		LIST[y].push_back (x);
	}
	fin.close();
	Biconex (st, -1);
	if (nf > 1)
		A[st] = 1;
	fout << nr;
	return 0;
}