#include <bits/stdc++.h>
using namespace std;
const long double pi = 3.1415926535897932384626433832795l;
template <typename T>
inline auto sqr(T x) -> decltype(x * x) {
  return x * x;
}
template <typename T1, typename T2>
inline bool umx(T1& a, T2 b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename T1, typename T2>
inline bool umn(T1& a, T2 b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
const int K = 23;
const int N = (1 << K);
int d[N];
pair<int, int> p[N];
int a[K];
int main() {
  cout.setf(ios::showpoint | ios::fixed);
  cout.precision(20);
  int n, m;
  cin >> n >> m;
  memset(a, 0, sizeof(a));
  for (int i = int(0); i < int(m); ++i) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    a[u] |= (1 << v);
    a[v] |= (1 << u);
  }
  if (m == n * (n - 1) / 2) {
    cout << 0 << endl;
    return 0;
  }
  for (int i = int(0); i < int(n); ++i) {
    a[i] |= (1 << i);
  }
  for (int i = int(0); i < int(N); ++i) {
    p[i] = make_pair(-1, -1);
  }
  memset(d, 1, sizeof(d));
  d[0] = 0;
  for (int i = int(0); i < int(n); ++i) {
    d[a[i]] = 1;
    p[a[i]] = make_pair(0, i);
  }
  for (int mask = int(0); mask < int((1 << n)); ++mask) {
    for (int j = int(0); j < int(n); ++j) {
      if (mask & (1 << j)) {
        if (umn(d[mask | a[j]], d[mask] + 1)) {
          p[mask | a[j]] = make_pair(mask, j);
        }
      }
    }
  }
  int tek = (1 << n) - 1;
  vector<int> ans;
  while (tek > 0) {
    ans.push_back(p[tek].second);
    tek = p[tek].first;
  }
  reverse((ans).begin(), (ans).end());
  cout << ans.size() << endl;
  for (int i = int(0); i < int(((int)(ans).size())); ++i) {
    cout << ans[i] + 1 << ' ';
  }
  cout << endl;
  return 0;
}
