#include <bits/stdc++.h>
using namespace std;
long long changeI(long long a) {
  long long k = 1;
  long long st = 0;
  while (a) {
    st =
        (st % 998244353 + ((a % 10) * (k % 998244353)) % 998244353) % 998244353;
    a /= 10;
    k *= 100;
  }
  return st;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long n, t = 0;
  cin >> n;
  vector<pair<long long, long long>> arr(n);
  for (long long i = 0; i < n; i++) {
    long long a;
    cin >> a;
    t += a;
    arr[i] = {a, i};
  }
  sort(arr.begin() + 1, arr.end());
  long long sum = arr[0].first;
  vector<long long> ans;
  ans.push_back(0);
  long long c = 0, p = n - 1;
  long long r = (t / 2) + 1;
  while (sum < r && p > 0) {
    if (arr[p].first * 2 <= arr[0].first) {
      sum += arr[p].first;
      ans.push_back(arr[p].second);
    }
    p--;
  }
  if (sum < r)
    cout << 0 << endl;
  else {
    cout << ans.size() << endl;
    for (auto i : ans) cout << 1 + i << " ";
    cout << endl;
  }
}
