УмнатаЛили

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

namespace _04.УмнатаЛили
{
    class Program
    {
        static void Main(string[] args)
        {
            int liLyYears = int.Parse(Console.ReadLine());
            decimal priceForLaundry = decimal.Parse(Console.ReadLine());
            decimal priceForToy = decimal.Parse(Console.ReadLine());
            decimal moneySaved = 0;
            int moneySavedCounter = 0;
            int toyCounter = 0;
            decimal result = 0;
            List<decimal> totalMoney = new List<decimal>();
            decimal brothertakesMoney = 0;
            for (int years = 1; years <= liLyYears; years++)
            {
                if (years % 2 == 0)
                {
                    moneySaved += 10;
                    brothertakesMoney++;
                    totalMoney.Add(moneySaved);
                    moneySavedCounter++;
                }
                else
                {
                    toyCounter++;
                }
            }
            result = (totalMoney.Sum() + toyCounter * priceForToy- brothertakesMoney*1);
            if (result >= priceForLaundry)
            {
                Console.WriteLine("Yes! {0:F2}", result - priceForLaundry);
            }
            else
            {
                Console.WriteLine("No! {0:F2}", priceForLaundry - result);
            }
        }
    }
}