import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        sc.nextLine();
        String c = sc.nextLine();

        int flag = 0;
        if(c.charAt(a) != '-'){
            flag++;
        }

        String d = c.substring(0,a);
        String e = c.substring(a+1,c.length());
        if(a != d.length() || b != e.length()){
            flag++;
            System.out.println(a);
            System.out.println(d.length());
            System.out.println(b);
            System.out.println(e.length());
        }
        int count =0;
        for(char x: c.toCharArray()){
            if(x == '-'){
                count++;
            }
        }
        if(count != 1){
            flag++;
        }
        if(flag == 0){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
    }
}
/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