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