fun main(args: Array<String>) {
    var (A, B) = readLine()!!.split(" ").map{it.toInt()}
    val S = readLine()!!
    for (i in 0..(A+B)) {
        if ((i==A)&&(S[i]!='-')) {
            println("No")
            return
        }
        if ((i!=A)&&(S[i] !in arrayOf('0', '1', '2', '3', '4', '5', '6', '7', '8', '9'))) {
            println("No")
            return
        }
    }
    println("Yes")
}
