using System;

namespace ConsoleApp17
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            double pricewashingmachine = double.Parse(Console.ReadLine());
            int p = int.Parse(Console.ReadLine());

            int totaltoy = 0;
            int totalbirthdaymoney = 0;
            int vsichko = 0;



            for (int i = 1; i <= n; i++ )
            {

                totaltoy = (i / 2)*p;


            }
            for (int i1 = 2; i1 <= n; i1 += 2)
            {
                totalbirthdaymoney += (i1 * 5) - 1;


            }
            vsichko = totaltoy + totalbirthdaymoney;

            if (vsichko >= pricewashingmachine)
            {

                double resto = vsichko - pricewashingmachine;
                Console.WriteLine($"Yes! {resto:f2}");




            }
            else
            {


                double nestiga = vsichko - pricewashingmachine;
                Console.WriteLine($"NO! {nestiga:f2}");


            }


        }
    }
}