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();

		String ans;
		if (s.length() == a + b + 1) {
			ans = "Yes";
			for (int i = 0; i < s.length(); i++) {
				if (i == a) {
					if (s.charAt(i) != '-') {
						ans = "No";
						break;
					}
				} else {
					if (s.charAt(i) == '-') {
						ans = "No";
						break;
					}
				}
			}
		} else {
			ans = "No";
		}
		System.out.println(ans);
		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