#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> a(n + 1);
  int sum = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  int target = (sum / 2) + 1;
  vector<int> ans;
  ans.push_back(1);
  target -= a[1];
  for (int i = 2; i <= n; i++) {
    if (a[i] * 2 <= a[1]) {
      target -= a[i];
      ans.push_back(i);
    }
  }
  if (target > 0) {
    cout << 0;
    return 0;
  }
  cout << ans.size() << '\n';
  for (int i = 0; i < ans.size(); i++) cout << ans[i] << " ";
  return 0;
}
