#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = (x << 1) + (x << 3) + (ch ^ 48);
    ch = getchar();
  }
  return x * f;
}
int n, m, k, a[23], f[1 << 22 + 1], ans[1 << 22 + 1], fa[1 << 22 + 1];
inline void Find(int s) {
  if (fa[s]) Find(fa[s]);
  printf("%d ", ans[s]);
}
vector<int> vec;
int main() {
  n = read(), m = read();
  for (int i = 1; i <= m; i++) {
    int u = read(), v = read();
    a[u] |= (1 << (v - 1));
    a[v] |= (1 << (u - 1));
  }
  memset(f, 0x3f, sizeof(f));
  for (int i = 1; i <= n; i++) {
    a[i] |= (1 << (i - 1));
    f[a[i]] = 1;
    ans[a[i]] = i;
  }
  if (m == (n * (n - 1) / 2)) {
    puts("0");
    return 0;
  }
  int maxn = (1 << n) - 1;
  for (int i = 0; i <= maxn; i++) {
    for (int j = 1; j <= n; j++) {
      if (!((1 << (j - 1)) & i)) continue;
      if (f[a[j] | i] > f[i] + 1) {
        f[a[j] | i] = f[i] + 1;
        fa[a[j] | i] = i;
        ans[a[j] | i] = j;
      }
    }
  }
  printf("%d\n", f[maxn]);
  Find(maxn);
  return 0;
}
