import scala.io.StdIn
object Main extends App {
  val Array(a, b) = StdIn.readLine().split(' ').map(_.toInt)
  val s = StdIn.readLine()
  val r = s.slice(0, a) + s.slice(a+1, s.length)
  //println(r)
  println(if(s.length == (a + b + 1) && s.charAt(a) == '-' && r.exists(p => p.isDigit)) "Yes" else "No")
}
