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

namespace ConsoleApplication15
{
    class Program
    {
        static void Main(string[] args)
        {
            var numberOfAdults = int.Parse(Console.ReadLine());
            var numberOfStudents = int.Parse(Console.ReadLine());
            var numberOfnights = int.Parse(Console.ReadLine());
            string typeOfTransport = Console.ReadLine();
            var transportExpenses = 0.0;
            var hotel = 0.0;
            var com = 0.0;
            var total = 0.0;

            if (typeOfTransport == "train")
            {
                if(numberOfAdults+numberOfStudents>=50)
                transportExpenses = ((numberOfAdults * 24.99 + numberOfStudents * 14.99)*2)/2;
                hotel = numberOfnights * 82.99;
                com = (transportExpenses + hotel) * 0.10;
                total = transportExpenses + hotel + com;
                Console.WriteLine("{0:F2}", total);


            }
            else if (typeOfTransport == "bus")
            {
                transportExpenses = (numberOfAdults * 32.50 + numberOfStudents * 28.50) * 2;
                hotel = numberOfnights * 82.99;
                com = (transportExpenses + hotel) * 0.10;
                total = transportExpenses + hotel + com;
                Console.WriteLine("{0:F2}", total);


            }
            else if (typeOfTransport == "boat")
            {
                transportExpenses = (numberOfAdults * 42.99 + numberOfStudents * 39.99) * 2;
                hotel = numberOfnights * 82.99;
                com = (transportExpenses + hotel) * 0.10;
                total = transportExpenses + hotel + com;
                Console.WriteLine("{0:F2}", total);

            }
            else if (typeOfTransport == "airplane")
            {
                transportExpenses = (numberOfAdults * 70.00 + numberOfStudents * 50.00) * 2;
                hotel = numberOfnights * 82.99;
                com = (transportExpenses + hotel) * 0.10;
                total = transportExpenses + hotel + com;
                Console.WriteLine("{0:F2}", total);

            }







        }
    }
}