Futures.scala

 def parallelPaper(lines: List[String]): Int = {
    val futures: List[Future[Int]] = for (line <- lines) yield parallelCompute(line)
    val result = futures.foldLeft(0) { (total, future) =>
      {
        future.onComplete {
          case Success(value) => {
            total + value
          }
          case Failure(e) => e.printStackTrace()
        }
        total
      }
    }
    Thread.sleep(1000)
    result
  }