#include <bits/stdc++.h>
using namespace std;
vector<int> g[30];
int n, m, dp[(1 << 22)];
int rec(int mask) {
  if (dp[mask] != -1) return dp[mask];
  if (mask == (1 << n) - 1) return dp[mask] = 0;
  int ans = n;
  if (mask == 0) {
    for (int i = 0; i < n; i++) {
      int curmask = mask;
      curmask |= (1 << i);
      for (int j = 0; j < g[i].size(); j++) {
        curmask |= (1 << g[i][j]);
      }
      if (mask != curmask) ans = min(ans, rec(curmask) + 1);
    }
  } else {
    for (int i = 0; i < n; i++) {
      if (mask & (1 << i)) {
        int curmask = mask;
        for (int j = 0; j < g[i].size(); j++) {
          curmask |= (1 << g[i][j]);
        }
        if (mask != curmask) ans = min(ans, rec(curmask) + 1);
      }
    }
  }
  return dp[mask] = ans;
}
void trace(int mask) {
  if (mask == (1 << n) - 1) return;
  int ans = rec(mask);
  if (mask == 0) {
    for (int i = 0; i < n; i++) {
      int curmask = mask;
      curmask |= (1 << i);
      for (int j = 0; j < g[i].size(); j++) {
        curmask |= (1 << g[i][j]);
      }
      if (mask != curmask && ans == 1 + rec(curmask)) {
        cout << i + 1 << ' ';
        trace(curmask);
        return;
      }
    }
  } else {
    for (int i = 0; i < n; i++) {
      if (mask & (1 << i)) {
        int curmask = mask;
        for (int j = 0; j < g[i].size(); j++) {
          curmask |= (1 << g[i][j]);
        }
        if (mask != curmask && ans == 1 + rec(curmask)) {
          cout << i + 1 << ' ';
          trace(curmask);
          return;
        }
      }
    }
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 0; i < (1 << n) - 1; i++) dp[i] = -1;
  for (int i = 1; i <= m; i++) {
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  bool bb = 1;
  for (int i = 0; i < n; i++) {
    if (g[i].size() != n - 1) {
      bb = 0;
      break;
    }
  }
  if (bb == 1) return cout << 0, 0;
  int ans = rec(0);
  cout << ans << "\n";
  trace(0);
}
