import java.util.Scanner;
public class Main {
public static void main(String[]srgs) {
	Scanner scan=new Scanner(System.in);
	int a=scan.nextInt();
	int b=scan.nextInt();
	String str=scan.next();
	boolean fig=true;
	for(int i=0;i!=a+b+1;i++) {
		char ch=str.charAt(i);
		if(i==a) {
			if(ch=='-') {
			}
			else {
				fig=false;
			}
		}
		else {
			if(ch=='-') {
				fig=false;
			}
		}
	}
	System.out.println(fig?"Yes":"No");
	scan.close();
}
}
/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