#include<iostream>#include<cstdio>#include<cstring>using namespace std;const int N=10010;struct Edge{ int to,nxt;}edge[N<<2];int head[N],vis[N],dfn[N],low[N],cut[N]; //cut[u] 表示u这个点割边数int cnt,k,root;void addedge(int cu,int cv){ edge[cnt].to=cv; edge[cnt].nxt=head[cu]; head[cu]=cnt++;}void Tarjan(int u,int fa){ //割点模板 int son=0; vis[u]=1; dfn[u]=low[u]=++k; for(int i=head[u];i!=-1;i=edge[i].nxt){ int v=edge[i].to; if(vis[v]==1 && v!=fa) low[u]=min(low[u],dfn[v]); if(!vis[v]){ Tarjan(v,u); son++; low[u]=min(low[u],low[v]); if((u==root && son>1) || (u!=root && dfn[u]<=low[v])) cut[u]++; //cut[u] 表示u这个点割边数 } } vis[u]=2;}int main(){ //freopen("input.txt","r",stdin); int n,m; while(~scanf("%d%d",&n,&m) && n){ if(m==0){ printf("%dn",n-1); continue; } memset(head,-1,sizeof(head)); memset(vis,0,sizeof(vis)); memset(cut,0,sizeof(cut)); memset(dfn,0,sizeof(dfn)); cnt=0; int u,v; while(m--){ scanf("%d%d",&u,&v); addedge(u,v); addedge(v,u); } int ans=0; int MAX=0; for(int i=0;i<n;i++){ if(!dfn[i]){ ans++; k=0; root=i; Tarjan(i,-1); } MAX=max(MAX,cut[i]); //取最大的 } printf("%dn",ans+MAX); } return 0;}
