#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n];
  int sum = 0;
  int num[n];
  int cou = 1;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  int koal = a[0];
  if (a[0] >= (sum / 2) + 1)
    cout << cou << '\n' << cou;
  else {
    for (int i = 1; i < n; i++) {
      if (a[0] >= (a[i] * 2)) {
        koal += a[i];
        num[cou++] = i + 1;
      }
    }
    if (koal >= (sum / 2) + 1) {
      cout << cou << '\n' << '1' << ' ';
      for (int i = 1; i < cou; i++) cout << num[i] << ' ';
    } else
      cout << '0';
  }
}
