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