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

class Program
{
    static void Main()
    {
        var n = long.Parse(ReadLine());
        var a =(long)Math.Sqrt(2*n);
        var b =false;
        var c =0L;
        for (long i = a; i < 9; i++)
        {
            if(i*(i+1)/2==n){
                b=true;
                c=i;
            }
        }
        WriteLine(b?"YES":"NO");
        if(b)WriteLine(c);
    }
}