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");
		}
	}
}
