#include<bits/stdc++.h>
using namespace std;
#define int long long
int n,m,cnt,p;
vector<int>v[100005];
int dfn[100005],low[100005];
bool ans[100005];
void tarjan(int x,bool root){
	int p=0;
	dfn[x]=low[x]=++cnt;
	for(int i=0;i<v[x].size();i++){
		int y=v[x][i];
		if(!dfn[y]){
			tarjan(y,0);
			low[x]=min(low[x],low[y]);
			if(low[y]>=dfn[x]&&!root) ans[x]=1;
			if(root) p++;
		}
		else{
			low[x]=min(low[x],dfn[y]);
		}
	}
	if(root&&p>=2) ans[x]=1;
	return;	
}
signed main(){
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		int u,vv;
		cin>>u>>vv;
		v[u].push_back(vv);
		v[vv].push_back(u);
	}
	for(int i=1;i<=n;i++){
		if(!dfn[i]) tarjan(i,1);
	}
	int h=0;
	for(int i=1;i<=n;i++){
		if(ans[i]) h++;
	}
	cout<<h<<endl;
	for(int i=1;i<=n;i++){
		if(ans[i]) cout<<i<<" ";
	}
	return 0;
}