#include <bits/stdc++.h>
using namespace std;
map<long long int, long long int> m1, m2;
map<long long int, long long int>::iterator itr, itr1;
bool cmp(const pair<long long int, long long int> &a,
         const pair<long long int, long long int> &b) {
  if (a.first < b.first) return true;
  return false;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  cin >> n;
  long long int arr[n];
  for (long long int i = 0; i < n; i++) cin >> arr[i];
  long long int sum = 0;
  for (long long int i = 0; i < n; i++) sum += arr[i];
  long long int z = (sum + 2) / 2;
  vector<pair<long long int, long long int> > v;
  for (long long int i = 1; i < n; i++) {
    if (arr[0] >= 2 * arr[i]) v.push_back(make_pair(arr[i], i + 1));
  }
  if (v.size() != 0) {
    sort(v.begin(), v.end(), cmp);
    reverse(v.begin(), v.end());
  }
  long long int ans = 0;
  long long int done = arr[0];
  vector<long long int> idx;
  for (long long int i = 0; i < v.size(); i++) {
    if (done >= z)
      break;
    else {
      idx.push_back(v[i].second);
      done += v[i].first;
    }
  }
  if (done < z)
    cout << "0" << endl;
  else {
    cout << idx.size() + 1 << endl;
    cout << "1 ";
    for (long long int i = 0; i < idx.size(); i++) cout << idx[i] << " ";
  }
  return 0;
}
