#include <bits/stdc++.h>
using namespace std;
int n, m;
int v[25];
void dfs(int &X, int s) {
  X ^= (1 << s);
  for (int i = 0; i <= 22; i++) {
    if ((1 << i) & X && (1 << i) & v[s]) {
      dfs(X, i);
    }
  }
}
void solve() {
  int ans = n;
  int ansV = (1 << n) - 1;
  int check;
  for (int i = 1; i < (1 << n); i++) {
    check = 0;
    if (__builtin_popcount(i) >= ans) continue;
    int all = 0;
    for (int j = 0; j <= 22; j++) {
      if ((1 << j) & i) all |= v[j];
    }
    if (__builtin_popcount(all) == n) {
      int X = i;
      dfs(X, __builtin_ctz(i));
      if (!X) check = 1;
    }
    if (check && __builtin_popcount(i) < ans) {
      ans = __builtin_popcount(i);
      ansV = i;
    }
  }
  cout << ans << "\n";
  for (int i = 0; i < 30; i++) {
    if (ansV & (1 << i)) cout << i + 1 << " ";
  }
  cout << "\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    v[a - 1] |= (1 << (b - 1));
    v[a - 1] |= (1 << (a - 1));
    v[b - 1] |= (1 << (a - 1));
    v[b - 1] |= (1 << (b - 1));
  }
  if (n == 0 || m == (n * (n - 1)) / 2) {
    cout << 0 << "\n";
    return 0;
  }
  solve();
}
