#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, sum = 0;
  cin >> n;
  vector<int> arr(n);
  for (int i = (int)0; i < (int)n; i++) {
    cin >> arr[i];
    sum += arr[i];
  }
  int ans = 1, major = arr[0];
  vector<int> coal;
  coal.push_back(1);
  for (int i = (int)1; i < (int)n; i++) {
    if (arr[0] >= arr[i] * 2) {
      major += arr[i];
      ans++;
      coal.push_back(i + 1);
    }
  }
  if (major > sum / 2) {
    cout << ans << endl;
    for (int i = (int)0; i < (int)ans; i++) {
      cout << coal[i] << ' ';
    }
  } else {
    cout << 0;
  }
}
