Back to the Past

using System;

namespace backToThePast
{
    class Program
    {
        static void Main(string[] args)
        {
            var money = double.Parse(Console.ReadLine());
            var year = int.Parse(Console.ReadLine());
            var startYear = 18;
            var constant = 12000;
            var calc = 0.0;

            for (int i = 1800; i <= year; i++)
            {
                startYear++;
                if (i%2==0)
                {
                    money -= constant;
                }
                else
                {
                    if (startYear%2==0)
                    {
                        startYear--;
                    }
                    calc = (startYear * 50) + constant;
                    money -= calc;
                }
            }
            if (money>=0)
            {
                Console.Write("Yes!");
                Console.WriteLine($" He will live a carefree life and will have {money:f2} dollars left.");
            }
            else
            {
                var plusExchange = Math.Abs(money);
                Console.WriteLine($"He will need {plusExchange:f2} dollars to survive.");
            }
        }
    }
}