#include<fstream>
#define Nmax 5001

using namespace std;

ifstream fin("biconex.in");
ofstream fout("biconex.out");

int n,a[Nmax][Nmax];
int dfn[Nmax],low[Nmax];
int numar_componente,nr_ordine;

void citire()
{int i,x,y,m;
fin>>n>>m;
for(i=1;i<=m;i++)
  {fin>>x>>y;
  a[x][0]++;
  a[x][a[x][0]]=y;
  a[y][0]++;
  a[y][a[y][0]]=x;
  }
}

int minim(int x,int y)
{if(x>y) return y;
return x;
}

void biconex(int u,int tatal)
{int x,i;
nr_ordine++;
dfn[u]=low[u]=nr_ordine;
for(i=1;i<=a[u][0];i++)
  {x=a[u][i];
   if(dfn[x]==0)
     {biconex(x,u);
     low[u]=minim(low[u],low[x]);
     if(low[x]>=dfn[u])
       numar_componente++;
     }
    else
      if(x!=tatal)
         low[u]=dfn[x];
  }
}

int main()
{citire();
biconex(3,-1);
fout<<numar_componente;
fin.close();
fout.close();
return 0;
}