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();
        String ans = "No";
        sc.close();
        try {
            Integer.parseInt(S.substring(0,A));
            Integer.parseInt(S.substring(A+1));
            if (S.length() == A+B+1){
                if (S.charAt(A) == '-'){
                    ans = "Yes";
                }
            }
        }
        catch(NumberFormatException e){
        }
        System.out.println(ans);
    }
}
/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