#include <bits/stdc++.h>
using namespace std;
using llong = long long;
const long long MXN = 1e6 + 7;
const long long INF = 2e18 + 7;
llong a[MXN];
int main() {
  vector<int> v;
  llong n, ans = 0, sum = 0;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  ans += a[1];
  v.push_back(1);
  for (int i = 2; i <= n; i++) {
    if (ans > sum / 2) {
      break;
    }
    if (a[1] / a[i] >= 2) {
      ans += a[i];
      v.push_back(i);
    }
  }
  if (ans <= sum / 2) {
    cout << 0;
    return 0;
  }
  cout << v.size() << endl;
  for (int i : v) {
    cout << i << ' ';
  }
  exit(0);
}
