//
// program to sum up numbers, entered from standard input
// ending with "quit"

// the next line is needed to avoid warnings with the newest Scala
// "comment it out" (insert a //) if you compile with an earlier version
import scala.io.StdIn._

def sum() : Int = {
  println("enter more numbers to add up, quit to stop")
  val n = readLine
  if (n == "quit")
    0
  else 
    n.toInt + sum()
}

println("sum is " + sum)