#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k = 1, other = 0, nij = 0, t = 1, tsit;
  cin >> n;
  int arr[n], sarr[n];
  cin >> arr[0];
  nij = arr[0];
  tsit = arr[0];
  sarr[0] = 1;
  for (int i = 1; i < n; i++) {
    int x;
    cin >> x;
    tsit = tsit + x;
    arr[i] = x;
    if (x <= arr[0] / 2) {
      k++;
      sarr[t++] = i + 1;
      nij = nij + x;
    } else
      other = other + x;
  }
  if (nij > tsit / 2) {
    cout << k << endl;
    for (int i = 0; i < t; i++) {
      cout << sarr[i] << " ";
    }
    cout << endl;
  } else
    cout << 0 << endl;
}
