import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a, b;
		String s;
		a = sc.nextInt();
		b = sc.nextInt();
		s = sc.next();

		for (int i = 0; i < a + b + 1; i++) {
			if(i != a && s.charAt(i) == '-') {
				System.out.print("No");
				return;
			} else if(i == a && s.charAt(i) != '-') {
				System.out.print("No");
				return;
			}
		}

		System.out.print("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