#include<bits/stdc++.h>
using namespace std;
int main()
{
	ios_base::sync_with_stdio(false);
	int n,m;
	cin>>n>>m;
	vector<pair<int,int>> edges;
	vector<vector<int>> G(n+5);
	vector<int> deg(n+5);
	for(int i=1;i<=m;i++)
	{
		int u,v;
		cin>>u>>v;
		edges.emplace_back(u,v);
		G[u].push_back(v);
		G[v].push_back(u);
		deg[u]++;deg[v]++;
	}
	for(int i=1;i<=n;i++)
	{
		if(deg[i]%2!=0)
		{
			cout<<0<<endl;
			return 0;
		}
	}
	if(n==m)
	{
		cout<<n<<endl;
		for(int i=1;i<=n;i++)
			cout<<i<<' ';
		return 0;
	}
	vector<int> p(n+5),vis(n+5),dfn(n+5),cnt(n+5);
	int cyc=0,ind=0;
	function<void(int)> dfs=[&](int u)
	{
		dfn[u]=++ind;vis[u]=1;
		for(auto v:G[u])
		{
			if(p[u]==v)continue;
			if(not vis[v])
			{
				p[v]=u;
				dfs(v);
			}
			else if(vis[v]==1)
			{
				cyc++;
				if(cyc<=2)
				{
					int x=u;
					cnt[x]++;
					while(x!=v)
					{
						x=p[x];
						cnt[x]++;
					}
				}
			}
		}
		vis[u]=2;
	};
	dfs(1);
	vector<int> tmp,tmp2;
	for(int i=1;i<=n;i++)
	{
		if(cnt[i]==2)
		{
			tmp2.push_back(i);
		}
	}
	sort(tmp2.begin(),tmp2.end(),[&](int u,int v){return dfn[u]<dfn[v];});
	if(tmp2.size()==1u)tmp.push_back(tmp2[0]);
	else if(tmp2.size()>=2u)tmp.push_back(tmp2.front()),tmp.push_back(tmp2.back());
	vector<int> ans;
	auto check=[&](int d)
	{
		vector<int> pa(n+5);
		function<int(int)> find=[&](int x){return pa[x]?pa[x]=find(pa[x]):x;};
		for(auto [u,v]:edges)
		{
			if(u==d or v==d)
				continue;
			int pu=find(u),pv=find(v);
			if(pu==pv)return false;
			pa[pv]=pu;
		}
		return true;
	};
	for(auto x:tmp)if(check(x))ans.push_back(x);
	cout<<ans.size()<<endl;
	for(auto z:ans)
	{
		cout<<z<<' ';
	}
	return 0;
}