Clever_Lily

using System;

namespace Clever_Lily
{
    class Program
    {
        static void Main(string[] args)
        {
            int ageOfLilly = int.Parse(Console.ReadLine());
            double priceOfLaundryM = double.Parse(Console.ReadLine());
            int priceToy = int.Parse(Console.ReadLine());

            int toys = 0;
            int money = 0;
            int totalMoney = 0;

            for (int iterator = 1; iterator <= ageOfLilly; iterator++)
            {
                money += 5;
                if (iterator % 2 == 0)
                {
                    totalMoney += money - 1;
                }
                else
                {
                    toys++;
                }

            }
            totalMoney += toys * priceToy;

            if (totalMoney >= priceOfLaundryM)
            {
                Console.WriteLine($"Yes! {totalMoney - priceOfLaundryM:F2}");
            }
            else
            {
                Console.WriteLine($"No! {priceOfLaundryM - totalMoney:F2}");
            }

        }
    }
}