object Main extends App {
  val sc = new java.util.Scanner(System.in)
  var a , b = sc.nextInt()
  var s = sc.next()
  if (s.take(a).indexOf('-') != -1){println("No");sys.exit()}
  s = s.drop(a)
  if (s(0) != '-'){println("No");sys.exit()}
  s = s.drop(1)
  if (s.take(b).indexOf('-') != -1){println("No");sys.exit()}
  s = s.drop(b)
  println(if(s == "") "Yes" else "No")
}
