Back to the Past fixed

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

namespace _4.BackToThePast
{
    class Program
    {
        static void Main(string[] args)
        {
            double heritage = double.Parse(Console.ReadLine());
            int yearToLive = int.Parse(Console.ReadLine());

            double yearsold = 17;

            for (int year = 1800; year <= yearToLive; year++)
            {
                if (year % 2 == 0)
                {
                    heritage = heritage - 12000;

                }
                else if(year % 2 != 0)
                {
                    yearsold += 2;
                    heritage = heritage - (12000 + (50 * yearsold));

                }

            }
            if (heritage >= 0)
            {
                Console.WriteLine("Yes! He will live a carefree life and will have {0:F2} dollars left.", heritage);
            }
            else
            {
                Console.WriteLine("He will need {0:F2} dollars to survive.", Math.Abs(heritage));
            }
        }
    }
}