#include <bits/stdc++.h>
using namespace std;
void coutv(vector<long long> v) {
  for (auto it : v) cout << it << " ";
  cout << endl;
}
int main() {
  long long n;
  cin >> n;
  vector<long long> v(n), idx;
  long long now, no;
  for (auto &i : v) cin >> i;
  now = v[0];
  no = 0;
  idx.push_back(1);
  for (int i = 1; i < n; i++) {
    if (v[i] <= v[0] / 2) {
      now += v[i];
      idx.push_back(i + 1);
    } else {
      no += v[i];
    }
  }
  if (now > no) {
    cout << idx.size() << endl;
    coutv(idx);
    return 0;
    ;
  }
  cout << 0 << endl;
}
