/* POJ2117 */

 #include <iostream>

 #include <vector>

 #include <algorithm>

 #include <cstdio>

 #include <cstring>

 #include <cstdlib>

 using namespace std;

 #define MAXN 10005

 vector<int> vc[MAXN];

 int low[MAXN], pre[MAXN];

 int n, m;

 int dfs_clock, ans, link;

 void init() {

     int i;

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

         vc[i].clear();

     memset(pre, , sizeof(int)*n);

     dfs_clock = ans = link = ;

 }

 void tarjan(int u, int fa) {

     int i, j, k, v;

     int child = ;

     int cnt = ;

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

     for (i=; i<vc[u].size(); ++i) {

         v = vc[u][i];

         if (!pre[v]) {

             ++child;

             tarjan(v, u);

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

             if (low[v] >= pre[u]) {

                 ++cnt;

             }

         } else if (pre[v]<pre[u] && v!=fa){

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

         }

     }

     if (fa == -) {

         if (child > )

             ans = max(ans, child-);

     } else {

         ans = max(ans, cnt);

     }

 }

 int main() {

     int i, j, k;

     #ifndef ONLINE_JUDGE

         freopen("data.in", "r", stdin);

         freopen("data.out", "w", stdout);

     #endif

     while (scanf("%d %d",&n,&m)!=EOF && (n||m)) {

         if (m == ) {

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

             continue;

         }

         init();

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

             scanf("%d %d", &j, &k);

             vc[j].push_back(k);

             vc[k].push_back(j);

         }

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

             if (!pre[i]) {

                 ++link;

                 tarjan(i, -);

             }

         }

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

     }

     return ;

 }