#include<iostream>

 #include<algorithm>

 #include<cstring>

 #include<cstdio>

 #include<sstream>

 #include<vector>

 #include<stack>

 #include<queue>

 #include<cmath>

 #include<map>

 #include<set>

 using namespace std;

 typedef long long ll;

 typedef pair<int,ll> pll;

 const int INF = 0x3f3f3f3f;

 const int maxn=+;

 int n, m;

 int tot;

 int dfs_clock;

 int pre[maxn];

 int cut[maxn];

 int low[maxn];

 int head[*maxn];

 int del;

 struct node

 {

     int v,next;

 }e[*maxn];

 void addEdge(int u, int v)

 {

     e[tot].v=v;

     e[tot].next=head[u];

     head[u]=tot++;

 }

 int tarjan(int u, int fa)

 {

     int lowu=pre[u]=++dfs_clock;

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

     {

         int v=e[i].v;

         if(v==del)  continue;

         if(!pre[v])

         {

             int lowv = tarjan(v,u);

             lowu=min(lowu,lowv);

             if(lowv>=pre[u])  cut[u]++;

         }

         else if(v!=fa)

             lowu=min(lowu,pre[v]);

     }

     if(fa<)  cut[u]--;

     return low[u]=lowu;

 }

 int solve()

 {

     int cnt=;

     dfs_clock=;

     memset(cut,,sizeof(cut));

     memset(pre,,sizeof(pre));

     for(int i=;i<n;i++)

     {

         if(del!=i && !pre[i])

         {

             cnt++;

             tarjan(i,-);

         }

     }

     int ans=;

     for(int i=;i<n;i++)

     {

         if(i!=del) ans=max(ans,cnt+cut[i]);

     }

     return ans;

 }

 int main()

 {

     //freopen("in.txt","r",stdin);

     while(~scanf("%d%d",&n,&m))

     {

         tot=;

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

         for(int i=;i<m;i++)

         {

             int u,v;

             scanf("%d%d",&u,&v);

             addEdge(u,v);

             addEdge(v,u);

         }

         int ans=-;

         for(int i=;i<n;i++)

         {

             del=i;

             ans=max(ans,solve());

         }

         printf("%d\n",ans);

     }

     return ;

 }