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 = double.Parse(Console.ReadLine());
            var price = -1.0;

            if (day=="saturday" || day=="sunday")
            {
                if (fruit == "banana") price = 2.70;
                else if (fruit == "apple") price = 1.25; //else if (fruit == "apple") price = 1.20;
                else if (fruit == "orange") price = 0.90;
                else if (fruit == "grapefruit") price = 1.60; //else if (fruit == "grapefruit") price = 1.45;

                else if (fruit == "kiwi") price = 3.00;
                else if (fruit == "pineapple") price = 5.60;
                else if (fruit == "grapes") price = 4.20; //   else if (fruit == "grapes") price = 3.85;
             }
            else if (day=="monday" || day=="tuesday" || day=="wednesday" || day=="thursday" || day=="friday")
            {
                if (fruit == "banana") price = 2.50;
                else if (fruit == "apple") price = 1.20;
                else if (fruit == "orange") price = 0.85;
                else if (fruit == "grapefruit") price = 1.45;
                else if (fruit == "kiwi") price = 2.70;
                else if (fruit == "pineapple") price = 5.50;
                else if (fruit == "grapes") price = 3.85;
            }
            if (price >= 0) // if (price>= -1.0)
                Console.WriteLine("{0:f2}" , price * quantity);
            else
                Console.WriteLine("error");
         }
     }
}