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 ar = sc.next();
String[] s = ar.split("");
               boolean flg = true;
		for(int i = 0; i < a; i++){
                     if( s[i].equals("-")) flg = false;
               }
               if ( !(s[a].equals("-"))) flg =false;
		for(int i = a+1; i < a+b+1; i++){
                     if( s[i].equals("-") )flg =false;
               }
              if (flg)                System.out.print("Yes");
             else  System.out.print("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