#include <bits/stdc++.h>
#pragma GCC optimize("-O3")
using namespace std;
void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  _main();
}
int N, M;
int dp[1 << 22];
int E[22];
int A[1 << 22], B[1 << 22];
void _main() {
  cin >> N >> M;
  for (int i = 0; i < N; i++) E[i] = 1 << i;
  for (int i = 0; i < M; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    E[a] += 1 << b;
    E[b] += 1 << a;
  }
  for (int i = 0; i < 1 << N; i++) dp[i] = 1010;
  dp[0] = 0;
  for (int msk = 0; msk < 1 << N; msk++) {
    int ok = 1;
    for (int i = 0; i < N; i++)
      if (msk & (1 << i)) {
        int m = msk & E[i];
        if (msk != m) ok = 0;
      }
    if (ok) dp[msk] = 0;
  }
  for (int msk = 0; msk < 1 << N; msk++) {
    int e = (1 << N) - 1;
    for (int i = 0; i < N; i++)
      if (msk & (1 << i)) {
        int nmsk = msk | E[i];
        if (dp[msk] + 1 < dp[nmsk]) {
          dp[nmsk] = dp[msk] + 1;
          A[nmsk] = msk;
          B[nmsk] = i;
        }
      }
  }
  printf("%d\n", dp[(1 << N) - 1]);
  vector<int> ans;
  int m = (1 << N) - 1;
  while (dp[m]) {
    ans.push_back(B[m]);
    m = A[m];
  }
  int n = ans.size();
  for (int i = 0; i < n; i++) {
    if (i) printf(" ");
    printf("%d", ans[n - 1 - i] + 1);
  }
  printf("\n");
}
