#include <bits/stdc++.h>
using namespace std;
const int N = 22;
int n, m, f[1 << N], g[N], preS[1 << N], prei[1 << N];
int main() {
  int i, j, S;
  scanf("%d%d", &n, &m);
  for (i = 0; i < n; ++i) g[i] |= 1 << i;
  for (i = 1; i <= m; ++i) {
    int x, y;
    scanf("%d%d", &x, &y);
    --x, --y;
    g[x] |= 1 << y;
    g[y] |= 1 << x;
  }
  if (n <= 2) return puts("0"), 0;
  for (i = 0; i < n; ++i)
    if (g[i] != (1 << n) - 1) break;
  if (i == n) return puts("0"), 0;
  memset(f, 255, sizeof(f));
  f[0] = 0;
  for (S = 0; S < (1 << n); ++S)
    if (~f[S]) {
      for (i = 0; i < n; ++i)
        if ((1 << i & S) || !S) {
          if (f[S | g[i]] < 0 || f[S] + 1 < f[S | g[i]]) {
            f[S | g[i]] = f[S] + 1;
            preS[S | g[i]] = S;
            prei[S | g[i]] = i;
          }
        }
    }
  printf("%d\n", f[(1 << n) - 1]);
  for (i = (1 << n) - 1; i; i = preS[i]) {
    printf("%d ", prei[i] + 1);
  }
  return 0;
}
