#include <iostream>
#include <fstream>
#include <vector>
#define NMax 100001
using namespace std;
ifstream fin("biconex.in");
ofstream fout("biconex.out");
vector <int> v[NMax];
int low[NMax], dfn[NMax];
bool viz[NMax];
int n, m, x, y, ordin, fii, compc, RAD;
void dfs(int nod, int Tnod) {
    ordin++;
    dfn[nod] = ordin;
    low[nod] = ordin ;
    viz[nod] = true;
    for(int i = 0; i < v[nod].size(); i++) {
        int fiu = v[nod][i];
        if(fiu == Tnod)
            continue;
        if(viz[fiu]) {
            low[nod] = min(low[nod], dfn[fiu]);
            continue;
        }
        if(nod == RAD) {
            fii++;
        }
        dfs(fiu, nod);
        low[nod] = min(low[nod], low[fiu]);
        if(low[fiu] >= dfn[nod]) {
            //cout<<nod<<' ';
            compc++;
        }
    }
}
int main()
{
    fin>>n>>m;
    for(int i = 1; i <= m; i++) {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    RAD = 1;
    dfs(1, 0);
    fout<<compc;
    /*
    for(int i = 1; i <= n; i++) {
        fout<<dfn[i]<<" ";
    }
    fout<<'\n';
    for(int i = 1; i <= n; i++) {
        fout<<low[i]<<" ";
    }
    */
    fin.close();
    fout.close();
    return 0;
}