Party Profit - TF MidExam 4Nov18

using System;

namespace _01PartyProfit
{
    class Program
    {
        static void Main(string[] args)
        {
            long partySize = long.Parse(Console.ReadLine());
            long days = long.Parse(Console.ReadLine());

            double coins = 0;

            for (int currDay = 1; currDay <= days; currDay++)
            {

                if (currDay % 10 == 0)
                {
                    partySize -= 2;
                }

                if (currDay % 15 == 0)
                {
                    partySize += 5;
                }

                coins += 50;
                coins -= (partySize * 2);

                if (currDay%3==0)
                {
                    coins -= partySize * 3;
                }

                if (currDay%5==0)
                {
                    coins += partySize * 20;

                    if (currDay%3==0)
                    {
                        coins -= partySize * 2;
                    }
                }

            }

            double coinsPerPerson =Math.Floor( coins / partySize);
            Console.WriteLine($"{partySize} companions received {coinsPerPerson} coins each.");
        }
    }
}