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

namespace ConsoleApplication8
{
    class Program
    {
        static void Main(string[] args)
        {
            var fruit = Console.ReadLine().ToLower();
            var dayOfWeek = Console.ReadLine().ToLower();
            var quantity = double.Parse(Console.ReadLine());

            if (dayOfWeek == "monday" || dayOfWeek == "tuesday" || dayOfWeek == "wednesday" || dayOfWeek == "thursday" || dayOfWeek == "friday")
            {
                if (fruit == "banana")
                {
                    Console.WriteLine(Math.Round(quantity * 2.5 , 2));
                }
                else if (fruit == "apple")
                {
                    Console.WriteLine(Math.Round(quantity * 1.2 , 2));
                }
                else if (fruit == "orange")
                {
                    Console.WriteLine(Math.Round(quantity * 0.85 , 2));
                }
                else if (fruit == "grapefruit")
                {
                    Console.WriteLine(Math.Round(quantity * 1.45 , 2));
                }
                else if (fruit == "kiwi")
                {
                    Console.WriteLine(Math.Round(quantity * 2.7 , 2));
                }
                else if (fruit == "pineapple")
                {
                    Console.WriteLine(Math.Round(quantity * 5.5 , 2));
                }
                else if (fruit == "grapes")
                {
                    Console.WriteLine(Math.Round(quantity * 3.85 , 2));
                }
            }
            else if (dayOfWeek == "saturday" || dayOfWeek == "sunday")
            {

                if (fruit == "banana")
                {
                    Console.WriteLine(Math.Round(quantity * 2.7 , 2));
                }
                else if (fruit == "apple")
                {
                    Console.WriteLine(Math.Round(quantity * 1.25 , 2));
                }
                else if (fruit == "orange")
                {
                    Console.WriteLine(Math.Round(quantity * 0.9 , 2));
                }
                else if (fruit == "grapefruit")
                {
                    Console.WriteLine(Math.Round(quantity * 1.6 , 2));
                }
                else if (fruit == "kiwi")
                {
                    Console.WriteLine(Math.Round(quantity * 3.00 , 2));
                }
                else if (fruit == "pineapple")
                {
                    Console.WriteLine(Math.Round(quantity * 5.6 , 2));
                }
                else if (fruit == "grapes")
                {
                    Console.WriteLine(Math.Round(quantity * 4.2 , 2));
                }

            }
            else
            {
                Console.WriteLine("error");
            }


        }
    }
}