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using System;

namespace Loops1100
{
    class Program
    {
        static void Main(string[] args)
        {
            //1.Read input
            int age = int.Parse(Console.ReadLine());
            double washPrice = double.Parse(Console.ReadLine());
            double priceToys = int.Parse(Console.ReadLine());
            double moneyFromBdays = 0;
            double moneyGift = 10;
            double numToys = 0;
            //2.Loop throuhg the bdays

            for (int birthday = 1; birthday <= age; birthday++)
            {
                //3.Check if the bday is even or odd
                if (birthday %2==0)
                {
                    moneyFromBdays += moneyGift;
                    moneyGift += 10;
                    moneyFromBdays --;
                }
                else
                {
                    numToys++;
                }
            }
            double totalMoneyFromToys = numToys * priceToys;
            double totalMoney = totalMoneyFromToys + moneyFromBdays;
            if (totalMoney >= washPrice)
            {
                Console.WriteLine($"Yes! {totalMoney-washPrice:f2}");
            }
            else
            {
                Console.WriteLine($"No! {washPrice-totalMoney:f2}");
            }
        }
    }
}