fun main(args: Array<String>) {
    val a = readLine()!!.split(" ").map { it.toInt() }.first()
    val s = readLine()!!
    
    println(if (s.isPostalCode(a)) "Yes" else "No")
}

fun String.isPostalCode(pre: Int): Boolean =
        this[pre] == '-' &&
                this.subSequence(0, pre).all(isNumber) &&
                this.subSequence(pre + 1, this.length).all(isNumber)

val isNumber: (Char) -> Boolean = { it in '0'..'9' }
