#include <bits/stdc++.h>
using namespace std;
inline long long mod(long long n, long long m) {
  long long ret = n % m;
  if (ret < 0) ret += m;
  return ret;
}
long long gcd(long long a, long long b) {
  return (b == 0LL ? a : gcd(b, a % b));
}
long long exp(long long a, long long b, long long m) {
  if (b == 0LL) return 1LL;
  if (b == 1LL) return mod(a, m);
  long long k = mod(exp(a, b / 2, m), m);
  if (b & 1LL) {
    return mod(a * mod(k * k, m), m);
  } else
    return mod(k * k, m);
}
int n, m;
const int N = 22;
int adj[N], grau[N];
bool isConnected[(1 << N)];
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    adj[b] |= (1 << a);
    adj[a] |= (1 << b);
    grau[a]++;
    grau[b]++;
  }
  if (m == n - 1) {
    int res = n;
    vector<int> v;
    for (int i = 0; i < n; i++)
      if (grau[i] <= 1) res--;
    cout << res << "\n";
    for (int i = 0; i < n; i++) {
      if (grau[i] > 1) cout << i + 1 << " ";
    }
    cout << "\n";
    return 0;
  }
  if (m == n * (n - 1) / 2) {
    cout << 0 << "\n";
    return 0;
  }
  for (int i = 0; i < n; i++) {
    adj[i] |= (1 << i);
    isConnected[(1 << i)] = 1;
  }
  int res = n;
  int best = 1;
  for (int msk = 0; msk < (1 << n); msk++) {
    if (isConnected[msk]) {
      int can = 0;
      for (int i = 0; i < n; i++) {
        if (msk & (1 << i)) can |= adj[i];
      }
      for (int i = 0; i < n; i++) {
        if ((msk & (1 << i)) == 0) {
          if (can & (1 << i)) {
            isConnected[msk ^ (1 << i)] = 1;
          }
        }
      }
      if (can == (1 << n) - 1) {
        int val = __builtin_popcount(msk);
        if (res > val) {
          res = val;
          best = msk;
        }
      }
    }
  }
  cout << res << "\n";
  for (int i = 0; i < n; i++) {
    if (best & (1 << i)) cout << i + 1 << " ";
  }
  cout << "\n";
}
