#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> a(n), ans;
  int tot = 0, coal = 0;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    tot += a[i];
    if (i == 0 || a[i] * 2 <= a[0]) {
      coal += a[i];
      ans.push_back(i);
    }
  }
  if (coal * 2 > tot) {
    cout << ans.size() << "\n";
    for (int id : ans) cout << id + 1 << " ";
    cout << endl;
  } else {
    cout << "0\n";
  }
}
