using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static void Main()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        if (m >= (long)n * (n + 1) / 2) WriteLine("Yes");
        else WriteLine("No");
    }
}