/*
TASK: zala
LANG: C++
*/
#include <stdio.h>
#include <vector>
using namespace std;
int min(int a, int b)
{
    return a>b?b:a;
}
bool crit[50000];
vector< vector<int> > g(50000);
int n, m;
int lowest[50000];
bool used[50000];
int cnt = 0;
int roots = 0;
void DFS(int k)
{
     used[k] = 1;
     lowest[k] = cnt++;
     for (int i = 0; i < g[k].size(); i++)
     {
         if (used[g[k][i]]) continue;
     
         DFS(g[k][i]);
         if (k == 0) roots++;
         else if (lowest[k] == lowest[g[k][i]]) crit[k] = 1;
     }
     
     for (int i = 0; i < g[k].size(); i++)
      lowest[k] = min(lowest[k], lowest[ g[k][i] ]);
}
         
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 0; i < m; i++)
    {
        int a, b;
        scanf("%d%d", &a, &b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
    
    DFS(0);
    
    int count = 0;
    for (int i = 1; i < n; i++)
     count += crit[i];
    if (roots > 1) count++;
    printf("%d\n", count);
    return 0;
}
    
    
