#include <bits/stdc++.h>
using namespace std;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
inline long long toll(string s) {
  long long v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T>
inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
int n, m;
vector<int> adj[23];
int memo[1 << 23];
int mskOf[23];
int solve(int msk) {
  if (msk == (1 << n) - 1) return 0;
  if (memo[msk] != -1) return memo[msk];
  int ans = 2e9;
  for (int i = 0; i < n; i++)
    if (msk & (1 << i)) {
      int tempMsk = msk;
      for (int v : adj[i]) tempMsk |= (1 << v);
      if (tempMsk != msk) ans = min(ans, 1 + solve(tempMsk));
    }
  return memo[msk] = ans;
}
void trace(int msk) {
  if (msk == (1 << n) - 1) return;
  int opt = solve(msk);
  for (int i = 0; i < n; i++) {
    if (msk & (1 << i)) {
      int tempMsk = msk;
      for (int v : adj[i]) tempMsk |= (1 << v);
      if (tempMsk != msk) {
        if (opt == 1 + solve(tempMsk)) {
          cout << i + 1 << " ";
          trace(tempMsk);
          return;
        }
      }
    }
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  int ans = 0;
  for (int i = 0; i < n; i++)
    if (adj[i].size() != n - 1) ans = 2e9;
  if (!ans) {
    cout << 0 << endl;
    return 0;
  }
  memset(memo, -1, sizeof(memo));
  for (int i = 0; i < n; i++) {
    int msk = (1 << i);
    for (int v : adj[i]) msk |= (1 << v);
    mskOf[i] = msk;
  }
  for (int i = 0; i < n; i++) ans = min(ans, 1 + solve(mskOf[i]));
  cout << ans << endl;
  for (int i = 0; i < n; i++) {
    if (ans == 1 + solve(mskOf[i])) {
      cout << i + 1 << " ";
      trace(mskOf[i]);
      return 0;
    }
  }
  return 0;
}
