#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
const int N = 22;
const int LG = 32 - __builtin_clz(N);
int adj[N];
bool is_con[(1 << 22)];
void solve() {
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    adj[a] = adj[a] | (1 << b);
    adj[b] = adj[b] | (1 << a);
  }
  for (int i = 0; i < n; i++) is_con[(1 << i)] = 1;
  for (int i = 1; i < (1 << n); i++) {
    if (is_con[i]) continue;
    int act = i;
    while (act > 0) {
      int dif = act & -act;
      int to = __builtin_ctz(dif);
      int bef = i - dif;
      if (is_con[bef] && (adj[to] & bef)) {
        is_con[i] = 1;
        break;
      }
      act -= dif;
    }
  }
  int ans = INF;
  int ind;
  for (int mask = 0; mask < (1 << n); mask++) {
    int num = __builtin_popcount(mask);
    if (num == 0) {
      bool flg = 1;
      for (int i = 0; i < n; i++) {
        if (adj[i] + (1 << i) != ((1 << n) - 1)) {
          flg = 0;
          break;
        }
      }
      if (flg) {
        cout << 0 << '\n';
        return;
      }
      continue;
    }
    if (!is_con[mask]) continue;
    bool flg = 1;
    for (int i = 0; i < n; i++) {
      if ((1 << i) & mask) continue;
      if ((adj[i] & mask) == 0) {
        flg = 0;
        break;
      }
    }
    if (flg) {
      if (ans > num) {
        ans = num;
        ind = mask;
      }
    }
  }
  cout << ans << '\n';
  for (int i = 0; i < n; i++)
    if (ind & (1 << i)) cout << i + 1 << " ";
  cout << '\n';
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(nullptr);
  int t = 1;
  while (t--) solve();
  return 0;
}
