import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        String s = sc.next();
        if (s.length() != a + b + 1){
            System.out.println("No");
        }

        String s1 = s.substring(0, a);
        char s2 = s.charAt(a);
        String s3 = s.substring(a+1);

        if (!s1.matches("[0-9]*")) {
            System.out.println("No");
            return;
        }
        if (s2 != '-') {
            System.out.println("No");
            return;
        }

        if (s3.matches("[0-9]*")) {
            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