#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
using namespace std;

const int INF = (int)1e9;
const int NEUTRALMIN = INF;
const int NEUTRALMAX = -INF;
const int MAXN = (int)1e5;
const int P = 239017;
const int MOD = 1000000007;

vector < vector <int> > gg;
bool used[MAXN];
int tin[MAXN];
int low_time[MAXN];
int cur_time;

vector <int> points;

void dfs(int v, int par) {
  int childs = 0;
  used[v] = true;
  tin[v] = cur_time;
  low_time[v] = cur_time++;
  bool point = false;

  for (int i = 0; i < (int)gg[v].size(); i++) {
    int to = gg[v][i];
    if (to == par)
      continue;
    if (!used[to]) {
      dfs(to, v);
      childs++;
      if (tin[v] <= low_time[to])
        point = true;
      else {
        low_time[v] = min(low_time[v], low_time[to]);
      }
    } else {
      // Found backedge
      low_time[v] = min(low_time[v], tin[to]);
    }
  }

  if ((par == -1 && childs > 1) || (par != -1 && point)) {
    points.push_back(v);
  }
}

void outputMe() {
  sort(points.begin(), points.end());
  points.resize(unique(points.begin(), points.end()) - points.begin());
  cout << points.size() << endl;
  for (int i = 0; i < (int)points.size(); i++) {
    cout << points[i] + 1 << " ";
  }
}

int main() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);

  int n, m, st;
  cin >> n >> m;
  gg.resize(n);
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    --a, --b;
    gg[a].push_back(b);
    gg[b].push_back(a);
    st = a;
  }

  for (int i = 0; i < n; i++) {
    if (!used[i])
      dfs(i, -1);
  }
  outputMe();

  return 0;
}