Mobile operator

using System;

namespace MobileOperator
{
    class Program
    {
        static void Main(string[] args)
        {
            string year = Console.ReadLine();
            string type = Console.ReadLine();
            string net = Console.ReadLine();
            int month = int.Parse(Console.ReadLine());

            double sum = 0;

            switch (type)
            {
                case "Small":
                    if (year == "one")
                    {
                        sum += 9.98;
                    }
                    else
                    {
                        sum += 8.58;
                    }
                    break;
                case "Middle":
                    if (year == "one")
                    {
                        sum += 18.99;
                    }
                    else
                    {
                        sum += 17.09;
                    }
                    break;
                case "Large":
                    if (year == "one")
                    {
                        sum += 25.98;
                    }
                    else
                    {
                        sum += 23.59;
                    }
                    break;
                case "ExtraLarge":
                    if (year == "one")
                    {
                        sum += 35.99;
                    }
                    else
                    {
                        sum += 31.79;
                    }
                    break;
            }


            if (net == "yes")
            {
                if (sum <= 10)
                {
                    sum += 5.5;
                }
                else if (sum > 10 && sum <= 30)
                {
                    sum += 4.35;
                }
                else
                {
                    sum += 3.85;
                }
            }

            double total = sum * month;

            if (year == "two")
            {
                total -= 3.75 * total / 100;
            }

            Console.WriteLine($"{total:F2} lv.");
        }
    }
}