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();
		boolean flag = true;
		if(s.length() != a + b + 1) {
			System.out.println("No");
			return;
		}
		for(int i = 0; i < a; i++) {
			if(s.charAt(i) < '0' || s.charAt(i) > '9') {
				flag = false;
				break;
			}
		}
		if(s.charAt(a) != '-') {
			flag = false;
		}
		for(int i = a + 1; i < a + b + 1; i++) {
			if(s.charAt(i) < '0' || s.charAt(i) > '9') {
				flag = false;
			}
		}
		if(flag) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
}
/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