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

namespace Fruit_Shop_if_
{
    class Program
    {
        static void Main(string[] args)
        {
            string fruit = Console.ReadLine().ToLower();
            string dayOfTheWeek = Console.ReadLine().ToLower();
            double num = double.Parse(Console.ReadLine());
            double result = -1;
            if (dayOfTheWeek == "monday" ||
                dayOfTheWeek == "tuesday" ||
                dayOfTheWeek == "wednesday" ||
                dayOfTheWeek == "thursday" ||
                dayOfTheWeek == "friday")
            {
                if (fruit == "banana")
                {
                    result = num * 2.5d;
                }
                else if (fruit == "apple")
                {
                    result = num * 1.2d;
                }
                else if (fruit == "orange")
                {
                    result = num * 0.85d;
                }
                else if (fruit == "grapefruit")
                {
                    result = num * 1.45d;
                }
                else if (fruit == "kiwi")
                {
                    result = num * 2.7d;
                }
                else if (fruit == "pineapple")
                {
                    result = num * 5.5d;
                }
                else if (fruit == "grapes")
                {
                    result = num * 3.85d;
                }
                else
                {
                    Console.WriteLine("error");
                }
            }
            else if (dayOfTheWeek == "sunday" ||
                dayOfTheWeek == "saturday")
            {
                if (fruit == "banana")
                {
                    result = num * 2.7d;
                }
                else if (fruit == "apple")
                {
                    result = num * 1.25d;
                }
                else if (fruit == "orange")
                {
                    result = num * 0.9d;
                }
                else if (fruit == "grapefruit")
                {
                    result = num * 1.6d;
                }
                else if (fruit == "kiwi")
                {
                    result = num * 3.0d;
                }
                else if (fruit == "pineapple")
                {
                    result = num * 5.6d;
                }
                else if (fruit == "grapes")
                {
                    result = num * 4.2d;

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

            if (result >= 0)
            {
                Console.WriteLine("{0:F2}", result);
            }

        }
    }
}