#include<bits/stdc++.h>
using namespace std;
const int maxn = 2e5+10;

int n,m;
struct{int nxt,v;}edge[maxn << 1];
int head[maxn],ec;
void add(int u,int v){edge[++ec]={head[u],ec},head[u]=ec;}
int dfn[maxn],low[maxn],dfc;
bool iscut[maxn];

template<bool is_fir=0>
void dfs(int u){
	dfn[u]=low[u]=++dfc;
	int sonc=0;
	for(int i=head[u];i;i=edge[i].nxt){
		int v=edge[i].v;
		if(!dfn[v]){
			++sonc;dfs(v);
			if(low[v]==dfn[v])iscut[u]=1;
			low[u]=min(low[u],low[v]);
		}else{
			low[u]=min(low[u],dfn[v]);
		}
	}
	if(is_fir)iscut[u]=(sonc>1);
}

signed main() {
	ios::sync_with_stdio(0),cin.tie(0);
	cin>>n>>m;
	for(int i=1,u,v;i<=m;++i)cin>>u>>v,add(u,v),add(v,u);
	for(int i=1;i<=n;++i)if(!dfn[i])dfs<1>(i);
	cout<<accumulate(iscut,end(iscut),0)<<'\n';
	for(int i=1;i<=n;++i)if(iscut[i])cout<<i<<' ';
}