#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, k, n, flag = 0;
  cin >> n;
  int a[n + 2];
  int sum = 0, var, total = 0;
  for (i = 0; i < n; i++) {
    cin >> a[i];
    total += a[i];
  }
  vector<int> v;
  var = a[0];
  v.push_back(1);
  sum += var;
  for (i = 1; i < n; i++) {
    if (a[i] * 2 <= var) {
      v.push_back(i + 1);
      sum += a[i];
    }
  }
  if (sum > total / 2) {
    cout << v.size() << endl;
    for (i = 0; i < v.size(); i++) cout << v[i] << " ";
  } else
    cout << 0 << endl;
}
