package main 
import (
        "fmt"
)

func main () {
        var a, b, an int
        var s string
        fmt.Scan(&a,&b,&s)
        for i := 0 ; i < a ; i++{
                ii := i + 1
                if s[i:ii] == "-"{
                        an +=1
                }
        }
        if s[a:b] != "-" {
                an +=1
        }
        for i := b ; i < a + b + 1 ; i++ {
                ii := i + 1
                if s[i:ii] == "-" {
                        an +=1
                }
        } 
        if an == 0 {
        fmt.Println("Yes")
        }  else if an != 0{
        fmt.Println("No")
        }
}
