#include <iostream>

 #include<cstdio>

 #include<cstring>

 #include<stack>

 #include<algorithm>

 #include<stdlib.h>

 using namespace std;

 #define N 1010

 #define M 2010

 struct node

 {

     int u,v,next;

 }edge[M];

 stack<int>s;

 int head[N],pre[N],low[N],sccno[N],scc,dep,t,de[N],vis[N],w[N][N];

 void init()

 {

     t = ;

     memset(head,-,sizeof(head));

     scc=;dep=;

     memset(sccno,,sizeof(sccno));

     memset(low,,sizeof(low));

     memset(pre,,sizeof(pre));

     memset(vis,,sizeof(vis));

 }

 void add(int u,int v)

 {

     edge[t].u = u;

     edge[t].v = v;

     edge[t].next = head[u];

     head[u] = t++;

 }

 void dfs(int u,int fa)

 {

     low[u] = pre[u] = ++dep;

     s.push(u);

     for(int i = head[u] ; i!=- ; i = edge[i].next)

     {

         int v = edge[i].v;

         if(v==fa) continue;

         if(!pre[v])

         {

             dfs(v,u);

             low[u] = min(low[u],low[v]);

         }

         else if(!sccno[v])

         low[u] = min(low[u],pre[v]);

     }

     if(low[u]==pre[u])

     {

         scc++;

         for(;;)

         {

             int x = s.top();s.pop();

             sccno[x] = scc;

             if(x==u) break;

         }

     }

 }

 int main()

 {

     int i,n,m,kk=;

     char str[];

     while(cin>>n>>m)

     {

         kk++;init();

         memset(w,,sizeof(w));

         memset(de,,sizeof(de));

         int a,b;

         while(m--)

         {

             scanf("%d%d",&a,&b);

             add(a,b);add(b,a);

         }

         dfs(,);

         for(i =  ; i < t  ; i++)

         {

             int u = edge[i].u,v = edge[i].v;

             if(!w[u][v]&&sccno[u]!=sccno[v])

             {

                 w[u][v]  = w[v][u]= ;

                 de[sccno[u]]++;

                 de[sccno[v]]++;

             }

         }

         int num=;

         for(i = ; i <= scc ; i++)

         if(de[i]==) num++;

         cout<<(num+)/<<endl;

     }

     return ;

 }