import java.util.*;

class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int A = Integer.parseInt(sc.next());
        int B = Integer.parseInt(sc.next());
        
        String[] s = sc.next().split("");
        
        if(!s[A].equals("-")){
            System.out.println("No");
            return;
        }
        
        for(int i=0; i<A; i++){
            if(s[i].equals("-")){
                System.out.println("No");
                return;
            }
        }
        
        for(int i=1; i<=B; i++){
            if(s[i + A].equals("-")){
                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