#include<bits/stdc++.h>

 using namespace std;

 #define R register int

 #define AC 1100

 #define ac 11000000

 int n, m, cnt, timer, ans;

 int q[AC], top;

 int q1[AC], head, tail;

 int belong[AC], low[AC], color[AC], dfn[AC];

 bool z[AC][AC], vis[AC];

 inline int read()

 {

     int x = ;char c = getchar();

     while(c > '' || c < '') c = getchar();

     while(c >= '' && c <= '') x = x *  + c - '', c = getchar();

     return x;

 }

 void pre()

 {

     n = read(), m = read();

     if(!n && !m) exit();

     memset(belong, , sizeof(belong));

     memset(vis, , sizeof(vis));

     memset(dfn, , sizeof(dfn));

     timer = cnt = ans = top = ;

     memset(z, , sizeof(z));

     int a, b;

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

     {

         a = read(), b = read();

         z[a][b] = z[b][a] = true;

     }

     for(R i = ; i <= n; i ++) z[i][i] = true;//不能走自环

 }

 inline void upmin(int &a, int b){

     if(b < a) a = b;

 }

 bool check(int x)//检查x所在点双是否是一个二分图

 {

     memset(color, , sizeof(color));

     head = tail = ;

     q1[++tail] = x, color[x] = ;

     while(head < tail)

     {

         x = q1[++head];

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

         {

             if(!z[x][i] && belong[i] == cnt)//如果有边并且在同一个点双中

             {

                 if(color[x] == color[i]) return false;

                 else if(!color[i]) q1[++tail] = i, color[i] = color[x] ^ ;

             }

         }

     }

     return true;

 }

 void tarjan(int x, int fa)//求点双联通分量

 {

     low[x] = dfn[x] = ++ timer;

     for(R i = ; i <= n; i ++)//枚举边

     {

         if(!z[x][i])

         {

             if(!dfn[i])

             {

                 q[++top] = i;//将这个点加入栈

                 tarjan(i, x);

                 upmin(low[x], low[i]);

                 if(low[i] >= dfn[x])//这个点是割点

                 {

                     int tot = ;//先加上割点和当前now的tot

                     belong[x] = ++ cnt;//先给这个割点临时打上标记

                     while(q[top] != i) ++tot, belong[q[top --]] = cnt;//记录下这个点所属的点双联通分量

                     belong[q[top --]] = cnt;

                     if(!check(x))//不是二分图，那么这个bcc当中的点都是合法的

                     {

                         int b = top + tot - ;//直接把刚取出来的点打上标记

                         vis[x] = true;//q[top] 不一定是割点

                         for(R i = top + ; i <= b; i ++) vis[q[i]] = true;

                     }

                 }

             }

             else if(i != fa) upmin(low[x], dfn[i]);

         }

     }

 }

 void work()

 {

     while()

     {

         pre();

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

             if(!dfn[i]) q[++top] = i, tarjan(i, i);//将当前点加入栈

         for(R i = ; i <= n; i ++) if(!vis[i]) ++ans;

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

     }

 }

 int main()

 {

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

     work();

 //    fclose(stdin);

     return ;

 }