import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String reg = "\\d+";

        int a = sc.nextInt();
        int b = sc.nextInt();
        String s = sc.next();
        boolean atrue = true;
        boolean btrue = true;
        boolean hi = true;

        for(int i=0; i<s.length(); i++){
            if(i < a && !Character.isDigit(s.charAt(i))){
                atrue = false;
            }

            if (i == a && !(s.charAt(i) == '-')){
                hi = false;
            }

            if(!Character.isDigit(s.charAt(i)) && i > a){
                btrue = false;
            }
        }

        if(atrue && btrue && hi){
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }

    public static void printListOneLine(List list){
        for(int i=0; i<list.size(); i++){
            System.out.println(list.get(i));
        }
    }

    public static void printList(List list){
        for(int i=0; i<list.size(); i++){
            if(i == list.size()){
                System.out.println(list.get(i));
            } else {
                System.out.print(String.format("%d ", list.get(i)));
            }
        }
    }

    public static void printArray(int[] array){
        for(int i=0; i<array.length; i++){
            if(i == array.length){
                System.out.println(array[i]);
            } else {
                System.out.print(String.format("%d ", array[i]));
            }
        }
    }

    public static int gcd(int a, int b){
        if (b == 0) return a;
        return gcd(b, a % b);
    }

    public static int lcm(int a, int b){
        return a * b / gcd(a, b);
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz