#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  vector<long long> v(n);
  long long sum = 0;
  for (long long i = 0; i < n; i++) {
    cin >> v[i];
    sum += v[i];
  }
  sum = sum / 2 + 1;
  vector<long long> ans;
  ans.push_back(0);
  long long p = v[0];
  for (long long i = 1; i < n; i++) {
    if (v[i] * 2 <= v[0]) {
      p += v[i];
      ans.push_back(i);
    }
  }
  if (p < sum)
    cout << 0;
  else {
    cout << ans.size() << endl;
    for (auto item : ans) cout << item + 1 << " ";
  }
}
