#include <bits/stdc++.h>
using namespace std;
const int N = 100100;
const int OO = 123456789;
int dp[1 << 22], previ[1 << 22], prevM[1 << 22], adj[22];
int main() {
  int n, m;
  scanf("%d%d", &n, &m);
  if (m == n * (n - 1) / 2) return printf("0\n"), 0;
  for (int i = 0; i < m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    u--, v--;
    adj[u] |= 1 << v, adj[v] |= 1 << u;
  }
  for (int i = 0; i < n; i++) adj[i] |= 1 << i;
  memset(dp, OO, sizeof dp);
  previ[0] = -1;
  dp[0] = 0;
  for (int mask = 0; mask < (1 << n); ++mask) {
    for (int i = 0; i < n; i++) {
      if (mask & 1 << i || !mask) {
        if (dp[mask | adj[i]] > dp[mask] + 1) {
          dp[mask | adj[i]] = dp[mask] + 1;
          previ[mask | adj[i]] = i;
          prevM[mask | adj[i]] = mask;
        }
      }
    }
  }
  printf("%d\n", dp[(1 << n) - 1]);
  int mask = (1 << n) - 1;
  while (previ[mask] != -1) {
    printf("%d ", previ[mask] + 1);
    mask = prevM[mask];
  }
  return 0;
}
