#include <bits/stdc++.h>
using namespace std;
int n, m, x, y;
int g[30];
int f[1 << 22];
int pres[1 << 22], prep[1 << 22];
int main() {
  scanf("%d%d", &n, &m);
  if (m == n * (n - 1) / 2) {
    printf("0");
    return 0;
  }
  for (int i = 1; i <= m; i++) {
    scanf("%d%d", &x, &y);
    g[x] |= 1 << y - 1;
    g[y] |= 1 << x - 1;
  }
  for (int i = 1; i <= n; i++) g[i] |= (1 << i - 1);
  memset(f, 63, sizeof(f));
  f[0] = 0;
  for (int S = 0; S < (1 << n); S++) {
    if (f[S] > 1e9) continue;
    for (int i = 0; i < n; i++) {
      if (S & (1 << i) || S == 0) {
        if (f[S | g[i + 1]] > f[S] + 1)
          f[S | g[i + 1]] = f[S] + 1, pres[S | g[i + 1]] = S,
                      prep[S | g[i + 1]] = i + 1;
      }
    }
  }
  printf("%d\n", f[(1 << n) - 1]);
  int t = (1 << n) - 1;
  while (t) {
    printf("%d ", prep[t]);
    t = pres[t];
  }
}
