import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        String str = sc.next();
        boolean flag = true;
        if (str.length() != a + b + 1) {
            flag = false;
        }
        if (str.charAt(a) != '-') {
            flag = false;
        }
        int count = 0;
        for (int i = 0; i < str.length(); i++) {
            if (str.charAt(i) == '-') {
                count++;
            }
        }
        if (count != 1) {
            flag = false;
        }
        System.out.println(flag ? "Yes" : "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