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

namespace Fruit_shop
{
    class Program
    {
        static void Main(string[] args)
        {

            var fruit = Console.ReadLine().ToLower();
            var day = Console.ReadLine().ToLower();
            var quantity = decimal.Parse(Console.ReadLine());


            string[] array1 = { "banana", "apple", "orange", "grapefruit", "kiwi", "pineapple", "grapes" };
            decimal[] prices = { 2.50M, 1.20M, 0.85M, 1.45M, 2.70M, 5.50M, 3.85M };
            decimal[] prices1 = { 2.70M, 1.25M, 0.90M, 1.60M, 3.00M, 5.60M, 4.20M };

            if ((day == "monday"|| day == "tuesday"|| day == "wednesday"|| day == "thursday"|| day == "friday")&&
                (fruit == "banana" || fruit == "apple" || fruit == "orange" || fruit == "grapefruit" || fruit == "kiwi" || fruit == "pineapple" || fruit == "grapes"))
            {
                for (int i = 0; i < array1.Length; i++)
                {
                    if (array1[i] == fruit)
                    {
                        decimal sum = prices[i];
                        Console.WriteLine(Math.Round((sum * quantity), 2));
                    }
                }

            }
            else if (day == "saturday"|| day == "sunday")
            {

                for (int i = 0; i < array1.Length; i++)
                {
                    if (array1[i] == fruit)
                    {
                        decimal sum = prices1[i];
                        Console.WriteLine(Math.Round ((sum * quantity),2));
                    }
                }
            }
            else
            {
                Console.WriteLine("error");
            }
        }
    }
}