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");
    }
}