import java.util.Scanner;

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

		} else {
			System.out.println("No");
			return;
		}
		s = s.substring(0, a)+s.substring(a+1);
		for(Character c : s.toCharArray()) {
			if(Character.isDigit(c)) {

			} else {
				System.out.println("No");
				return;
			}
		}
		System.out.println("Yes");
	}
}