import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		try (Scanner sc = new Scanner(System.in);) {
			int a = sc.nextInt();
			int b = sc.nextInt();
			String s = sc.next();
			String ans = "No";
          sc.close();

			Integer.parseInt(s.substring(0, a));
			Integer.parseInt(s.substring(a + 1));
			if (s.length() == a + b + 1) {
				if (s.charAt(a) == '-') {
					ans = "Yes";
				}
			}
			System.out.println(ans);
		}

	}

}
