#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return (a * b) / gcd(a, b); }
long long poww(long long a, long long b) {
  if (b == 0) return 1;
  long long tmp = poww(a, b / 2);
  return (b & 1 ? a * tmp * tmp : tmp * tmp);
}
string itos(long long i) {
  string s = "";
  while (i) {
    s += char(i % 10 + '0');
    i /= 10;
  }
  reverse(s.begin(), s.end());
  return s;
}
long long stoi(string &s) {
  long long tot = 0;
  for (int i = (int)s.length() - 1, j = 1; i >= 0; i--, j *= 10) {
    tot += j * (s[i] + '0');
  }
  return tot;
}
int months[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
using namespace std;
void tt() { freopen("test.txt", "r", stdin); }
int mod = 1e9 + 7;
const int MAX = 1e6 + 10;
int n, m;
int dp[(1 << 22) + 10], ok[(1 << 22) + 10];
vector<int> conn[30];
int main() {
  cin >> n >> m;
  if (m == (n * (n - 1)) / 2) {
    return cout << 0 << '\n', 0;
  }
  for (int i = 1; i <= m; i++) {
    int x, y;
    cin >> x >> y;
    conn[x - 1].push_back(y - 1);
    conn[y - 1].push_back(x - 1);
  }
  for (int mask = 0; mask < (1 << n); mask++) {
    for (int j = 0; j < n; j++) {
      if (!mask) {
        int mmask = mask;
        mmask += (1 << j);
        for (auto t : conn[j]) mmask |= (1 << t);
        if (!dp[mmask]) {
          dp[mmask] = dp[mask] + 1;
          ok[mmask] |= (1 << j);
        } else {
          if (dp[mmask] > dp[mask] + 1) {
            dp[mmask] = dp[mask] + 1;
            ok[mmask] = (ok[mask] | (1 << j));
          }
        }
      } else if (dp[mask]) {
        if (mask & (1 << j)) {
          int mmask = mask;
          for (auto t : conn[j]) mmask |= (1 << t);
          if (!dp[mmask]) {
            dp[mmask] = dp[mask] + 1;
            ok[mmask] = (ok[mask] | (1 << j));
          } else {
            if (dp[mmask] > dp[mask] + 1) {
              dp[mmask] = dp[mask] + 1;
              ok[mmask] = (ok[mask] | (1 << j));
            }
          }
        }
      }
    }
  }
  cout << dp[(1 << n) - 1] << '\n';
  int mask = ok[(1 << n) - 1];
  for (int i = 0; i < n; i++)
    if (mask & (1 << i)) {
      cout << i + 1 << " ";
    }
  cout << '\n';
  return 0;
}
