#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
ifstream f("biconex.in");
ofstream g("biconex.out");

const int Nmax = 100005;
int n, m, use[Nmax], Level[Nmax], Low[Nmax], nr, sol;
bool punct[Nmax];
vector <int> G[Nmax];

void Read()
{
    f>>n>>m;
    while(m--)
    {
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int nod, int tata)
{
    int nrsons = 0;
    Level[nod] = Low[nod] = Level[tata]+1;
    use[nod] = 1;
    for(int i = 0; i < (int)G[nod].size(); i++)
    {
        int vecin = G[nod][i];
        if(vecin == tata) continue;
        if(!use[vecin])
        {
            nrsons++;
            DFS(vecin, nod);
            Low[nod] = min(Low[nod], Low[vecin]);
            if(Low[vecin] >= Level[nod] && tata!=0 && punct[nod] == 0)
            {
                punct[nod] = 1;
                nr++;
            }
        }
        else Low[nod] = min(Low[nod], Level[vecin]);
    }
    if(tata == 0 && nrsons > 1 && punct[nod] == 0)
    {
        nr++;
        punct[nod] = 1;
    }
}

void Solve()
{
    for(int i = 1; i <= n; i++)
    {
        if(!use[i])
        {
            nr = 0;
            DFS(i,0);
            sol = sol+nr+1;
        }
    }
}

void Print()
{
    g<<sol<<'\n';
}

int main()
{
    Read();
    Solve();
    Print();
    return 0;
}