#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long int n, a, tot = 0, coa = 0;
  cin >> n;
  cin >> a;
  tot = a;
  coa = a;
  long long int arr[n - 1];
  vector<long long int> ans;
  for (long long int i = 0; i < n - 1; i++) {
    cin >> arr[i];
    tot += arr[i];
    if (a >= 2 * arr[i]) {
      coa += arr[i];
      ans.push_back(i + 2);
    }
  }
  if (coa > tot / 2) {
    cout << ans.size() + 1 << endl << 1 << " ";
    for (long long int i : ans) cout << i << " ";
  } else
    cout << 0;
}
