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

namespace Vacation
{
    class Program
    {
        static void Main(string[] args)
        {
            int adults = int.Parse(Console.ReadLine());
            int students = int.Parse(Console.ReadLine());
            int nights = int.Parse(Console.ReadLine());
            string transport = Console.ReadLine().ToLower();
            double adultsPay = 0;
            double studentsPay = 0;
            double discount = 1;
            if (adults + students >= 50)
            {
                discount = 0.5;
            }

            if (transport == "train")
            {
                adultsPay = 24.99;
                studentsPay = 14.99;
            }
            else if (transport == "bus")
            {
                adultsPay = 32.50;
                studentsPay = 28.50;
            }
            else if (transport == "boat")
            {
                adultsPay = 42.99;
                studentsPay = 39.99;
            }
            else if (transport == "airplane")
            {
                adultsPay = 70.00;
                studentsPay = 50.00;
            }
            double transportPrice = (adults * adultsPay + studentsPay * students) * discount;
            double hotelPrice = 82.99 * nights;
            double totalPayWithCommision = (transportPrice * 2 + hotelPrice) * 1.10;
            Console.WriteLine("{0:f2}", totalPayWithCommision);
        }
    }
}