using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace cleverLily
{
    class Program
    {
        static void Main(string[] args)
        {

            int ageLily = int.Parse(Console.ReadLine());
            double wash = double.Parse(Console.ReadLine());
            double toyPrice = double.Parse(Console.ReadLine());
            double money = 0;

            double moneyMax = 0;

            int brotherTake = 0;
            int numToy = 0;

            for (int itoy = 1; itoy <= ageLily; itoy++)
            {
                if (itoy % 2 == 1)
                {
                    numToy++;
                }
            }
            double allToyPrice = toyPrice * numToy;


            for (int imoney = 1; imoney <= ageLily; imoney++)
            {

                if (imoney % 2 == 0)
                {
                    money += 10;
                    moneyMax += money;
                    brotherTake++;

                }

            }

            double allMoney = allToyPrice + moneyMax - brotherTake;
            //Console.WriteLine(moneyMax);
            //Console.WriteLine(allToyPrice);
            //Console.WriteLine(allMoney);

            if (wash <= allMoney)
            {
                Console.WriteLine($"Yes! {(allMoney - wash):F2}");
            }
            else
            {
                Console.WriteLine($"No! {(wash - allMoney):F2}");
            }
        }
    }
}