#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, c = 0, sum = 0;
  cin >> n;
  int a[n];
  vector<int> v1;
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  sum = sum / 2;
  c++;
  sum -= a[0];
  v1.push_back(1);
  for (long long i = 0; i < n; i++) {
    if (sum >= 0 && a[i] <= a[0] / 2) {
      c++;
      v1.push_back(i + 1);
      sum -= a[i];
    }
  }
  if (sum < 0) {
    cout << c << endl;
    for (long long x = 0; x < v1.size(); x++) {
      cout << v1[x] << " ";
    }
  } else
    cout << 0;
  return 0;
}
