#include <bits/stdc++.h>
using namespace std;
const int M = 30;
int read() {
  int x;
  scanf("%d", &x);
  return x;
}
int n, m, a[M], dp[1 << 22], fa[1 << 22], g[1 << 22];
void print(int x) {
  if (!x) return;
  print(fa[x]);
  printf("%d ", g[x]);
}
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);
  }
  if (m == n * (n - 1) / 2) {
    puts("0");
    return 0;
  }
  memset(dp, 0x3f, sizeof dp);
  for (int i = 1; i <= n; i++) {
    a[i] |= (1 << i - 1);
    dp[a[i]] = 1;
    g[a[i]] = i;
  }
  for (int i = 1; i < (1 << n); i++) {
    for (int j = 1; j <= n; j++)
      if (i & (1 << j - 1) && dp[i | a[j]] > dp[i] + 1) {
        dp[i | a[j]] = dp[i] + 1;
        g[i | a[j]] = j;
        fa[i | a[j]] = i;
      }
  }
  printf("%d\n", dp[(1 << n) - 1]);
  print((1 << n) - 1);
}
