import java.util.Scanner;

public class Main {

	public static void main(String... nui) {
		
		Scanner sc = new Scanner(System.in);
		
		int a = sc.nextInt();
		int b = sc.nextInt();
		String s = sc.next();
		
		for (int i = 0; i < s.length(); i++) {
			
			if (i == a) continue;
			
			if (s.charAt(i) < '0' || s.charAt(i) > '9') {
				
				System.out.println("No");
				return;
				
			}
			
		}
		
		System.out.println((s.charAt(a) == '-') ? "Yes" : "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