rt

#include<bits/stdc++.h>
using namespace std;
vector<int> v;
int n,m;
struct Edge
{
	int to,next;
};
Edge edge[2000005];
int cnt,head[200004];
void add(int fr,int to)
{
	cnt++;
	edge[cnt].to=to;
	edge[cnt].next=head[fr];
	head[fr]=cnt;
}
int low[200004],deep[200004];
void dfs1(int x,int fa)
{
	deep[x]=low[x]=deep[fa]+1;
	int js=0;
	for(int i=head[x];i;i=edge[i].next)
	{
		int y=edge[i].to;
		if(y==fa)
		{
			continue;
		}
		if(deep[y]==0)
		{
			dfs1(y,x);
			low[x]=min(low[x],low[y]);
			if(low[y]>=deep[x]&&fa!=0)
			{
				v.push_back(x);
			}
		}
		else
		{
			low[x]=min(low[x],deep[y]);
		}
	}
	if(fa==0&&js>=2)
	{
		v.push_back(x);
	}
	//cout<<x<<" "<<deep[x]<<" "<<low[x]<<"\n";
}
int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);
	cin>>n>>m;
	for(int i=1;i<=m;i++)
	{
		int x,y;
		cin>>x>>y;
		add(x,y);
		add(y,x);
	}
	for(int i=1;i<=n;i++)
	{
		if(deep[i]==0)
		{
			dfs1(i,0);
		}
	}
	//cout<<v.size()<<"\n";
	sort(v.begin(),v.end());
	v.erase(unique(v.begin(),v.end()),v.end());
	cout<<v.size()<<"\n";
	for(int i=0;i<v.size();i++)
	{
		cout<<v[i]<<" ";
	}
	return 0;
}