var boatsList = List[String]("321x13", "2x2", "3x3")
  var boats = List[Tuple2[Int, Int]]()
  var amount = 0
  var size = 0
  var xIndex = 0

  for(boat <- boatsList){
    xIndex = boat.indexOf('x')
    amount = boat.substring(0, xIndex).toInt
    size = boat.substring(xIndex + 1, boat.length).toInt

    boats = boats :+ (amount, size)
  }

  println(boats)