#include <bits/stdc++.h>
using namespace std;
int n, a[100005], sum, u, sum1;
vector<pair<int, int> > v;
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  sum1 += a[1];
  for (int i = 1; i <= n; i++) {
    if (a[i] * 2 <= a[1]) v.push_back({a[i], i});
  }
  for (int i = 0; i < v.size(); i++) sum1 += v[i].first;
  if (sum1 * 2 <= sum)
    cout << 0 << endl;
  else {
    cout << v.size() + 1 << endl;
    cout << 1 << " ";
    for (int i = 0; i < v.size(); i++) cout << v[i].second << " ";
  }
}
