#include<stdio.h>
#include<string.h>
#define max(a,b) (a>b?a:b)
#define min(a,b) (a>b?b:a)
struct s
{
	int u,v,next;
}edge[10010];
int head[5050],dfn[5050],low[5050],n,m,time,sum,ans,cnt,del,iscnt[5050];
void init()
{
	time=cnt=sum=ans=0;
	memset(head,-1,sizeof(head));
	//	memset(vis,0,sizeof(vis));
	memset(iscnt,0,sizeof(iscnt));
}
void add(int u,int v)
{
	edge[cnt].u=u;
	edge[cnt].v=v;
	edge[cnt].next=head[u];
	head[u]=cnt++;
}
void tarjan(int u,int pre)
{
	low[u]=dfn[u]=time++;
	int i,j;
	for(i=head[u];i!=-1;i=edge[i].next)
	{
		int v=edge[i].v;
		if(v==del)
			continue;
		if(dfn[v]==-1)
		{
			tarjan(v,u);
			low[u]=min(low[v],low[u]);
			if(low[v]>=dfn[u])
				iscnt[u]++;
		}
		else
		{
			if(dfn[v]<dfn[u]&&v!=u)
			{
				low[u]=min(low[u],dfn[v]);
			}
		}
	}
	if(pre<0)
		iscnt[u]--;
}
int main()
{
	while(scanf("%d%d",&n,&m)!=EOF)
	{
		int i,j;
		init();
		for(i=0;i<m;i++)
		{
			int u,v;
			scanf("%d%d",&u,&v);
			add(u,v);
			add(v,u);
		}
		for(i=0;i<n;i++)
		{
			del=i;
			time=0;
			memset(low,-1,sizeof(low));
			memset(dfn,-1,sizeof(dfn));
			memset(iscnt,0,sizeof(iscnt));
			sum=0;
			for(j=0;j<n;j++)
			{
				if(j==del)
					continue;
				if(dfn[j]==-1)
				{
					tarjan(j,-1);
					sum++;
				}
			}
			for(j=0;j<n;j++)
			{
				if(j==del)
					continue;
			//	printf("%d %d %d \n",sum,j,iscnt[j]);
				ans=max(ans,sum+iscnt[j]);
			}
		}
		printf("%d\n",ans);
	}
}