import scala.io._
def toInt(in: String): Option[Int] =
 try {
 Some(Integer.parseInt(in.trim))
 } catch {
 case e: NumberFormatException => None
 }
def sum(in: Seq[String]) = {
 val ints = in.flatMap(s => toInt(s))
 ints.foldLeft(0)((a, b) => a + b)
}
println("Enter some numbers and press ctrl-D (Unix/Mac) ctrl-C (Windows)")
val input = Source.fromInputStream(System.in)
val lines = input.getLines.collect
println("Sum "+sum(lines))