#include <bits/stdc++.h>
using namespace std;
int n, m;
int G[27];
bool bylo[(1 << 22)];
int sas[(1 << 22)];
int wynik = 100;
int gd;
int wszystkie;
void f(int x) {
  if (bylo[x]) return;
  bylo[x] = 1;
  for (int i = 0; i < n; ++i) {
    if ((x & (1 << i)) == 0 && (sas[x] & (1 << i)) != 0) {
      f(x | (1 << i));
    }
  }
  if (sas[x] == wszystkie) {
    int rr = __builtin_popcount(x);
    if (rr < wynik) {
      wynik = rr;
      gd = x;
    }
  }
}
int main() {
  cin >> n >> m;
  wszystkie = (1 << n) - 1;
  for (int i = 1; i <= m; ++i) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    G[a] |= (1 << b);
    G[b] |= (1 << a);
  }
  for (int i = 0; i < n; ++i) G[i] |= (1 << i);
  for (int x = 1; x < (1 << n); ++x) {
    int v = __builtin_ctz(x);
    sas[x] = sas[x ^ (1 << v)] | G[v];
  }
  bool klika = 1;
  for (int i = 0; i < n; ++i)
    if (G[i] != wszystkie) klika = 0;
  if (klika)
    wynik = 0;
  else
    for (int i = 0; i < n; ++i) f(1 << i);
  cout << wynik << endl;
  for (int i = 0; i < n; ++i)
    if (gd & (1 << i)) cout << (i + 1) << ' ';
  cout << endl;
  return 0;
}
