import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        String s = scan.next();
        if(s.charAt(a)!='-')
        {
            System.out.println("No");
            return;
        }
        for(int i=0;i<a;i++)
        {
            if(s.charAt(i)=='-')
            {
                System.out.println("No");
                return;
            }
        }
        for(int j=a+1;j<a+b+1;j++)
        {
            if(s.charAt(j)=='-')
            {
                System.out.println("No");
                return;
            }
        }
        System.out.println("Yes");
    }    
}
/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