#include <iostream>
#include <cstdio>
#include <vector>
#include <bitset>
#include <stack>
#define N 200005
using namespace std;
vector <int> G[N];
stack < pair <int,int> >stiva;
bitset <N> viz;
vector < int >aux;
vector < vector <int> >sol;
int x,y,n,m,nr=0,sus[N],niv[N],k;
void dfs(int st,int tata)
{
    viz[st]=1;
    niv[st]=niv[tata]+1;
    sus[st]=niv[st];
    vector <int>::iterator it;
    for(it=G[st].begin();it!=G[st].end();++it)
        {
            if(*it==tata)
                continue;
            else if(!viz[*it])
                    {
                        stiva.push(make_pair(st,*it));
                        dfs(*it,st);
                        sus[st]=min(sus[st],sus[*it]);
                        if(sus[*it]>=niv[st])
                            k++;
                    }
            else
                sus[st]=min(sus[st],sus[*it]);
        }

}
void citire()
{
    scanf("%d %d\n",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d %d\n",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}
void afisare()
{
    printf("%d",k);

}
int main()
{
    freopen("biconex.in","r",stdin);
    freopen("biconex.out","w",stdout);
    citire();
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
            dfs(i,0);
    }
    afisare();
    //cout << "Hello world!" << endl;
    return 0;
}