#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int arr[n];
  int sum = 0;
  int total = 0;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    total += arr[i];
    if (i > 0) sum += arr[i];
  }
  vector<int> ans;
  ans.push_back(1);
  int alice_sum = arr[0];
  bool can = false;
  for (int i = 1; i < n; i++) {
    if (alice_sum > total / 2) {
      can = true;
      break;
    }
    if (2 * arr[i] <= arr[0]) {
      alice_sum += arr[i];
      ans.push_back(i + 1);
      if (alice_sum > total / 2) {
        can = true;
        break;
      }
    }
  }
  if (can) {
    cout << ans.size() << endl;
    for (int i = 0; i < ans.size(); i++) {
      cout << ans[i] << " ";
    }
  } else {
    cout << 0;
  }
  return 0;
}
