#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int ar[n], ans[n], rsum = 0, i;
  for (i = 0; i < n; i++) {
    cin >> ar[i];
    rsum += ar[i];
  }
  int sum = ar[0], j = 0;
  if (sum > rsum / 2) {
    cout << "1" << endl << "1";
    return 0;
  } else {
    for (i = 1; i < n; i++) {
      if (ar[0] >= ar[i] * 2) {
        sum += ar[i];
        ans[j] = i + 1;
        j++;
      }
      if (sum > rsum / 2) break;
    }
  }
  if (sum <= rsum / 2)
    cout << "0";
  else {
    cout << j + 1 << endl << "1 ";
    for (i = 0; i < j; i++) cout << ans[i] << " ";
  }
  return 0;
}
