import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		String s = sc.next();
		char[] cs = s.toCharArray();
		int cnt = 0;

		if (String.valueOf(cs[a]).equals("-")) {
			for (int i = 0; i < a; i++) {
				if (Character.isDigit(cs[i])) {
					cnt++;
				}
			}
			for (int i = (a + 1); i <= (a + b); i++) {
				if (Character.isDigit(cs[i])) {
					cnt++;
				}
			}
			if (cnt == (a + b)) {
				System.out.println("Yes");
			} else {
				System.out.println("No");
			}
		} else {
			System.out.println("No");
		}

		sc.close();
	}

}
/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