#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using db = double;
using pii = pair<int, int>;
const int mxn = 23;
int pcnt(int x) { return __builtin_popcount(x); }
int n, m;
int e[mxn];
int f[1 << 22];
int main() {
  cin >> n >> m;
  if (m == n * (n - 1) / 2) {
    puts("0");
    puts("");
    return 0;
  }
  for (int i = 0; i < n; ++i) e[i] |= (1 << (i));
  for (int i = 0; i < m; ++i) {
    int x, y;
    scanf("%d%d", &x, &y);
    --x, --y;
    e[x] |= (1 << (y));
    e[y] |= (1 << (x));
  }
  int u = (1 << (n)) - 1;
  int s = u;
  for (int i = 0; i <= u; ++i)
    if (!i || f[i]) {
      if (f[i] == u && pcnt(i) < pcnt(s)) s = i;
      for (int j = 0; j < n; ++j)
        if ((~i >> j & 1) && (!i || (f[i] >> j & 1)))
          f[i | (1 << (j))] = f[i] | e[j];
    }
  cout << pcnt(s) << endl;
  for (int i = 0; i < n; ++i)
    if (s >> i & 1) cout << i + 1 << ' ';
  cout << endl;
  return 0;
}
