package main

import (
	"fmt"
)

func main() {
	var a, b int
	var s string
	fmt.Scan(&a, &b, &s)

	result := "No"
	if string(s[a]) == "-" {
		for i := 0; i < a; i++ {
			if string(s[i]) == "0" || string(s[i]) == "1" || string(s[i]) == "2" || string(s[i]) == "3" || string(s[i]) == "4" || string(s[i]) == "5" || string(s[i]) == "6" || string(s[i]) == "7" || string(s[i]) == "8" || string(s[i]) == "9" {
				result = "Yes"
			} else {
				result = "No"
				fmt.Println(result)
				return
			}
		}
		for i := a + 1; i < b; i++ {
			if string(s[i]) == "0" || string(s[i]) == "1" || string(s[i]) == "2" || string(s[i]) == "3" || string(s[i]) == "4" || string(s[i]) == "5" || string(s[i]) == "6" || string(s[i]) == "7" || string(s[i]) == "8" || string(s[i]) == "9" {
				result = "Yes"
			} else {
				result = "No"
				fmt.Println(result)
				return
			}
		}
		fmt.Println(result)
	} else {
		result = "No"
		fmt.Println(result)
		return
	}

}
