#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int arr[n + 2];
  long long int sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    sum += arr[i];
  }
  if ((sum / 2) < arr[0]) {
    cout << 1 << '\n' << 1 << endl;
    return 0;
  }
  vector<int> v;
  long long int sum1 = 0;
  for (int i = 1; i < n; i++) {
    if (arr[i] * 2 <= arr[0]) {
      v.push_back(i + 1);
      sum1 += arr[i];
    }
  }
  sum1 += arr[0];
  if (v.size() == 0)
    cout << 0 << endl;
  else {
    if (sum / 2 >= sum1) {
      cout << 0 << endl;
      return 0;
    }
    cout << v.size() + 1 << endl;
    cout << 1 << " ";
    for (int i = 0; i < v.size(); i++) cout << v[i] << " ";
    cout << endl;
  }
  return 0;
}
