fun solve(a:Int, b:Int, s:String): Boolean {
    if (s.count { it=='-'} != 1)
        return false
    val idx = s.indexOf('-' )

    return idx == a && s.length==(a+b+1)
}

fun main(args: Array<String>) {
    val (a, b) = readLine()!!.split(" ").map { it.toInt() }
    val S = readLine()!!

    val ans = if(solve(a,b,S)) "Yes" else "No"
    println(ans)

}