#include <bits/stdc++.h>
using namespace std;
int e[25];
int f[1 << 22], pres[1 << 22], prep[1 << 22];
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, m;
  cin >> n >> m;
  for (int i = 1; i <= m; i++) {
    int u, v;
    cin >> u >> v;
    e[u] |= 1 << (v - 1);
    e[v] |= 1 << (u - 1);
  }
  if (m == n * (n - 1) / 2) {
    cout << "0";
    return 0;
  }
  for (int i = 1; i <= n; i++) e[i] |= 1 << (i - 1);
  memset(f, 63, sizeof(f));
  f[0] = 0;
  for (int s = 0; s < (1 << n); s++) {
    for (int i = 0; i < n; i++) {
      if (s & (1 << i) || s == 0) {
        if (f[s | e[i + 1]] > f[s] + 1)
          f[s | e[i + 1]] = f[s] + 1, pres[s | e[i + 1]] = s,
                      prep[s | e[i + 1]] = i + 1;
      }
    }
  }
  cout << f[(1 << n) - 1] << "\n";
  int t = (1 << n) - 1;
  while (t) {
    cout << prep[t] << " ";
    t = pres[t];
  }
}
