#include <bits/stdc++.h>
#define int long long
#define pb(x) push_back(x)
using namespace std;
const int N = 100005;

int n,m,par[N],cnt=0;
vector<int> a[N];
vector<int> res;
int num[N],low[N];

void dfs(int u)
{
    int x = (par[u] != -1);
    num[u]=low[u]=++cnt;
    for(int &v : a[u])
    {
        if (v == par[u]) continue;
        if (par[v]) low[u] = min(low[u],num[v]);
        else
        {
            par[v]=u;
            dfs(v);
            low[u]=min(low[u],low[v]);
            if (low[v] >= num[u]) ++x;
        }
    }
    if (x >= 2) res.pb(u);
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    freopen("cnode.inp","r",stdin);
    freopen("cnode.out","w",stdout);
    cin >> n >> m;
    for(int i=1; i<=m; ++i)
    {
        int u,v;
        cin >> u >> v;
        a[u].pb(v);
        a[v].pb(u);
    }
    for(int i=1; i<=n; ++i)
    {
        if (!par[i])
        {
            par[i]=-1;
            dfs(i);
        }
    }
    cout << res.size() << endl;
    for(int &i : res) cout << i << " ";
    return 0;
}