import java.util.*;
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();
		if (s.matches("[0-9]{"+a+"}-[0-9]{"+b+"}")) System.out.println("Yes");
		else System.out.println("No");
        sc.close();
	}
}