import java.util.*;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int A,B,accept=0;
        String S;
        A=sc.nextInt();
        B=sc.nextInt();
        S=sc.next();
        for(int a=0;a<A+B+1;a++){
            if(S.charAt(a)=='-') accept++;
        }
        if(S.charAt(A)=='-'&&accept==1) 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