/*Tarjan求割点 */#include<iostream>#include<cstdio>#include<cstring>#include<stack>#define maxn 10010using namespace std;int n,m,num,head[maxn],low[maxn],dfn[maxn],f[maxn],father[maxn];int point[maxn],topt,sum;struct node{    int v,pre;}e[maxn*200];stack<int>s;int init(){    int x=0;char s=getchar();    while(s<‘0‘||s>‘9‘)s=getchar();    while(s>=‘0‘&&s<=‘9‘){x=x*10+s-‘0‘;s=getchar();}    return x;}void Clear(){    memset(head,0,sizeof(head));    memset(low,0,sizeof(low));    memset(dfn,0,sizeof(dfn));    memset(f,0,sizeof(f));    memset(point,0,sizeof(point));    num=topt=sum=0;    while(!s.empty())s.pop();}void Add(int from,int to){    num++;e[num].v=to;    e[num].pre=head[from];    head[from]=num;}void Tarjan(int x,int fa){    father[x]=fa;    dfn[x]=low[x]=++topt;    f[x]=1;s.push(x);    int sc=0;    for(int i=head[x];i;i=e[i].pre){        int v=e[i].v;        if(dfn[v]==0){            sc++;            Tarjan(v,x);low[x]=min(low[x],low[v]);            if(low[v]>=dfn[x])            point[x]++;        }        else if(f[v])low[x]=min(low[x],dfn[v]);    }    if(fa<0&&sc==1)point[x]=0;    if(low[x]==dfn[x]){        while(s.top()!=x){            f[s.top()]=0;s.pop();        }        f[s.top()]=0;s.pop();    }}void Init(){    for(int i=1;i<=m;i++){        int u,v;        u=init();v=init();        u++;v++;        Add(u,v);Add(v,u);    }    for(int i=1;i<=n;i++)        if(dfn[i]==0){            sum++;Tarjan(i,-1);        }}void Solve(){    int mxx=-100000;    for(int u=1;u<=n;u++){        if(father[u]==-1){            point[u]--;        }        mxx=max(mxx,point[u]);    }    printf("%d\n",sum+mxx);}int main(){    while(1){        n=init();m=init();        if(n==0&&m==0)break;        Clear();        Init();        Solve();    }}