object main extends App {
  def loop(in : Stream[Int]) : Int =
    if (in.length == 1)
      in.head
    else {
      println(in.take(20).toList)
      loop(
        in.zip(Stream.from(1)).filter { case (_, i) =>
          ((i % 2) == 0) && ((i % 4) != 0)
        }.map(_._1)
      )
    }
  println(loop(1.to(2018).toStream))
}