#include <bits/stdc++.h>
using namespace std;
int main() {
  int count = 0, n, i, req, k, temp;
  int *seats;
  std::vector<int> vec;
  cin >> n;
  seats = new int[n];
  count = 0;
  for (int i = 0; i < n; i++) {
    cin >> seats[i];
    count = count + seats[i];
  }
  req = count / 2 + 1;
  k = 1;
  vec.push_back(1);
  temp = seats[0];
  bool flag = false;
  for (int i = 1; i < n; i++) {
    if (seats[0] >= 2 * seats[i]) {
      temp = temp + seats[i];
      k++;
      vec.push_back(i + 1);
    }
    if (temp >= req) {
      flag = true;
      break;
    }
  }
  if (flag) {
    cout << k << endl;
    for (int i = 0; i < vec.size(); i++) {
      cout << vec[i] << " ";
    }
  } else
    cout << "0";
  delete seats;
}
