#include <iostream>
#include <cstdio>
#include <vector>
#include <set>
#include <bitset>

using namespace std;

const int NodMax = 100005;
const int MuchMax = 200005;
int N, M, cmp_biconexe;
int tov[NodMax], low[NodMax];
bitset < NodMax > viz;
set < int > Puncte;
vector < int > G[NodMax];
//tov = time of visit = cand gasesc prima oara nodul x
//low = nivel cel mai mic la care poate ajunge nodul x

void Read()
{
    scanf("%d %d", &N, &M);

    for(int i=1; i<=M; ++i)
    {
        int x, y;
        scanf("%d %d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int nod, int dad)
{
    tov[nod] = 1 + tov[dad];
    low[nod] = tov[nod];

    viz[nod] = 1;
    vector < int > ::iterator it;
    for(it=G[nod].begin(); it!=G[nod].end(); ++it)
    {
        if( *it == dad)
            continue;

        else
            if(!viz[*it])
        {
            DFS(*it, nod);
            low[nod] = min(tov[*it], low[nod]);
            if(tov[nod] <= low[*it])
                {
                 Puncte.insert(nod);
                }
        }

        else
            low[nod] = min(low[nod], low[*it]);
    }
}

int main()
{
    freopen("biconex.in", "r", stdin);
    freopen("biconex.out", "w", stdout);
    Read();

    for(int i=1; i<=N; ++i)
    {
        if(!viz[i])
        {
            DFS(i,0);
        }
    }

    cout << Puncte.size() <<"\n";

    set < int > ::iterator it;
    for (it=Puncte.begin(); it!=Puncte.end(); ++it)
        cout << *it << " ";
    return 0;
}