import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int a = in.nextInt();
		int b = in.nextInt(); in.nextLine();
		String s = in.nextLine();
		String ans = "No";
		if( s.contains("-") ) {
			String[] arr = s.split("-");
			if( arr.length == 2 ) {
				if( arr[0].length() == a && arr[1].length() == b ) ans = "Yes";
			}
		}
		System.out.println(ans);
	}

}
/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