import java.util.Scanner

object Main {
  def isNum(ch: Char): Boolean = {
    val ret = ch match {
      case '0' => true
      case '1' => true
      case '2' => true
      case '3' => true
      case '4' => true
      case '5' => true
      case '6' => true
      case '7' => true
      case '8' => true
      case '9' => true
      case _ => false
    }
    return ret
  }
  def main(args: Array[String]): Unit = {
    val sc = new Scanner(System.in)
    val a, b = sc.nextInt()
    val s = sc.next()
//    println(s)
    var f = true
    for(i <- 0 until a) {
      f = isNum(s(i))
//      println(i)
    }
    if(f) {
//      println("Yes")
    } else {
      println("No")
      return
    }
    f = if(s(a)!='-') {
      false
    } else {
      true
    }
    if(f) {
//      println("Yes")
    } else {
      println("No")
      return
    }
//    println(a + " " + b)
    for(i <- a+1 until a+b+1) {
      f = isNum(s(i))
//      println(i)
    }
    if(f) {
      println("Yes")
    } else {
      println("No")
    }
  }
}
