#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, sum = 0;
  cin >> n;
  vector<long long int> v, ans;
  for (long long int i = 0; i < n; i++) {
    long long int a;
    scanf("%lld", &a);
    v.push_back(a);
    sum += a;
  }
  long long int kop = v[0];
  ans.push_back(1);
  for (long long int i = 1; i < n; i++) {
    long long int a = v[0] / 2;
    if (v[i] <= a) {
      kop += v[i];
      ans.push_back(i + 1);
    }
  }
  long long int joss = sum / 2 + 1;
  if (kop < joss) {
    cout << "0" << endl;
  } else {
    cout << ans.size() << endl;
    for (long long int i = 0; i < ans.size(); i++) cout << ans[i] << " ";
    cout << endl;
  }
}
