#include<cstdio>
#include<algorithm>
#include<iostream>
#include<cmath>
#include<vector>
using namespace std;
int n,m;
vector<int> mp[2000005];
bool dix[2000005];
int dfn[2000005],low[2000005];
int tot,ans;
void Tarjan(int x,int fa,int root){
	int len = mp[x].size();
	dfn[x] = low[x] = ++tot;
	int flag = 0;
	for(int i = 0;i < len;i++){
		int y = mp[x][i];
		if(!dfn[y]){
			Tarjan(y,x,root);
			low[x] = min(low[x],low[y]);
			if(low[y] >= dfn[x]) {
				flag++;
				if(flag > 2 && x != root){
					if(!dix[x]) ans++;
					dix[x] = 1;
				}
			}
		}
		else if(y != fa) low[x] = min(low[x],dfn[y]);
	}
	return ;
}
int main(){
	scanf("%d%d",&n,&m);
	for(int i = 1;i <= m;i++){
		int u,v;
		scanf("%d%d",&u,&v);
		mp[u].push_back(v);
		mp[v].push_back(u);
	}
	for(int i = 1;i <= n;i++){
		if(!dfn[i]) Tarjan(i,0,i);
	}
	printf("%d\n",ans);
	for(int i = 1;i <= n;i++){
		if(dix[i]) printf("%d ",i);
	}
	return 0;
}