#include<bits/stdc++.h>
using namespace std;
int n,m;
int u[500005],v[500005];
vector<pair<int,int> > to[100005];
int ans[500005],an;
int dfn[100005],low[100005];
void dfs(int nx,int fr)
{
	low[nx]=dfn[nx]=++dfn[0];
	bool b=0;
	int cnt=0;
	for(auto i:to[nx])
	{
		if(i.second==fr)	continue;
		if(dfn[i.first])	low[nx]=min(low[nx],dfn[i.first]);
		else
		{
		++cnt;
			dfs(i.first,i.second);
			low[nx]=min(low[nx],low[i.first]);
			if(low[i.first]>=dfn[nx])	b=1;
		}
	}
	if((b&&fr)||(cnt>=2&&!fr))	ans[++an]=nx;
}
int main()
{
	freopen("11.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++)
	{
		int x,y;
		scanf("%d%d",&x,&y);
		u[i]=x;
		v[i]=y;
		to[x].push_back({y,i});
		to[y].push_back({x,i});
	}
	for(int i=1;i<=n;i++)
	{
		if(!dfn[i])	dfs(i,0);
	}
	sort(ans+1,ans+an+1);
	cout<<an<<'\n';
	for(int i=1;i<=an;i++)
	{
		cout<<ans[i]<<' ';
	}
	return 0;
}