using System;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApp1
{
    public static class MyExtensions
    {
        public static string Slice(this string str, int start = 0, int stop = 0)
        {
            if (start > str.Length || stop > str.Length || start < 0 || stop < 0)
                return "";

            if (stop == 0) stop = str.Length;
            return str.Substring(start, stop - start);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            ABC084_B();
        }

        static void ABC084_B()
        {
            var AB = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            var S = Console.ReadLine();
            if (S.Slice(0, S.IndexOf('-')).Count() == AB[0] &&
                S.Slice(S.IndexOf('-') + 1, S.Length).Count() == AB[1])
                Console.WriteLine("Yes");
            else
                Console.WriteLine("No");
        }
    }
}