#include <bits/stdc++.h>
using namespace std;
const int M = 1 << 22;
int read() {
  int x = 0, f = 1;
  char c;
  while ((c = getchar()) < '0' || c > '9') {
    if (c == '-') f = -1;
  }
  while (c >= '0' && c <= '9') {
    x = (x << 3) + (x << 1) + (c ^ 48);
    c = getchar();
  }
  return x * f;
}
int n, m, a[30], dp[M], fa[M], g[M];
void print(int x) {
  if (fa[x]) print(fa[x]);
  printf("%d ", g[x]);
}
signed 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);
}
