SmartLili

using System;

namespace SmarLili
{
    class Program
    {
        static void Main(string[] args)
        {
            int lilisAge = int.Parse(Console.ReadLine());
            double washingMachinePrice = double.Parse(Console.ReadLine());
            int priceOfSingleToy = int.Parse(Console.ReadLine());

            int moneyFromFather = 0;
            int countOfToys = 0;
            int moneyBrotherStole = 0;
            for (int currentYear = 1; currentYear <= lilisAge; currentYear++)
            {
                if (currentYear % 2 == 0)
                {
                    moneyFromFather += (currentYear * 10) / 2;
                    moneyBrotherStole++;
                }
                else
                {
                    countOfToys++;
                }
            }

            int totalMoneySaved = (moneyFromFather - moneyBrotherStole) + (countOfToys * priceOfSingleToy);

            double moneyDiff = Math.Abs(totalMoneySaved - washingMachinePrice);
            if (totalMoneySaved >= washingMachinePrice)
            {
                Console.WriteLine($"Yes! {moneyDiff:f2}");
            }
            else
            {
                Console.WriteLine($"No! {moneyDiff:f2}");
            }
        }
    }
}