#include <bits/stdc++.h>
#pragma GCC optimize("-O3")
using namespace std;
void no(int ex = 0);
const int N = 1e5 + 5;
const int mod = 987654321;
int n, m, k, T;
int p, q;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  vector<int> vec;
  cin >> k;
  vec.push_back(1);
  m = k;
  int sum = k;
  for (int i = 0; i < (int)n - 1; i++) {
    cin >> q;
    sum += q;
    if (k >= q * 2) {
      m += q;
      vec.push_back(i + 2);
    }
  }
  if (m > sum / 2) {
    cout << vec.size() << "\n";
    for (int i = 0; i < vec.size(); i++) cout << vec[i] << " ";
  } else
    no();
}
void no(int ex) {
  cout << ex << "\n";
  exit(0);
}
