#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n];
  cin >> a[0];
  int total = a[0], coalition = a[0];
  vector<int> c;
  c.push_back(1);
  for (int i = 1; i < n; i++) {
    cin >> a[i];
    total += a[i];
    coalition += a[i];
    if (2 * a[i] <= a[0])
      c.push_back(i + 1);
    else
      coalition -= a[i];
  }
  if (a[0] > total / 2) {
    cout << "1 1"
         << "\n";
    return 0;
  }
  if (coalition <= total / 2) {
    cout << "0"
         << "\n";
    return 0;
  }
  cout << c.size() << "\n";
  for (int i = 0; i < c.size(); i++) cout << c[i] << " ";
  cout << "\n";
  return 0;
}
