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