using System;
using System.Linq;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Text;
 
public class Program
{
    public void Proc() {
        Reader.IsDebug = false;
        long[] inpt = Reader.ReadLine().Split(' ').Select(a=>long.Parse(a)).ToArray();
        int itemCount = (int)inpt[0];
        decimal heikin = (decimal)inpt[1];

        decimal[] items = Reader.ReadLine().Split(' ').Select(a=>decimal.Parse(a)).ToArray();
        if(heikin == items.Average()) {
            Console.WriteLine("YES");
        } else {
            Console.WriteLine("NO");
        }
    }






    public class Reader {
        public static bool IsDebug = true;
        private static System.IO.StringReader SReader;
        private static string InitText = @"


3 5
4 5 6


";
        public static string ReadLine() {
            if(IsDebug) {
                if(SReader == null) {
                    SReader = new System.IO.StringReader(InitText.Trim());
                }
                return SReader.ReadLine();
            } else {
                return Console.ReadLine();
            }
        }
    }
    public static void Main(string[] args)
    {
        Program prg = new Program();
        prg.Proc();
    }
}