7

object Codewars {
   def helper(i:Int, s:String,l:Int,s1:String):String= {
    val c=s.charAt(i).toLower
    if (i < l - 1){ val s2 =s1+s.charAt(i).toUpper + s"$c" * i+'-'
      helper(i + 1, s, l,s2)
    }
    else{ val s2 =s1+s.charAt(i).toUpper + s"$c" * i
      if (i == l-1) { return s2}
      else helper(i + 1, s, l,s2)
    }
  }
  def accum(s: String):String = {
    val l = s.length()
    val i=0
    val s1=""
    helper(i,s,l,s1)
  }
}