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

namespace FruitShop
{
    class Program
    {
        static void Main(string[] args)
        {
            String type = Console.ReadLine().ToLower();
            String day = Console.ReadLine().ToLower();
            double ammount = double.Parse(Console.ReadLine());

            if (day.Equals("sunday") || day.Equals("saturday"))
            {
                switch (type)
                {
                    case "banana":
                        Console.WriteLine("{0:0.00}",2.70 * ammount);
                        break;
                    case "apple":
                        Console.WriteLine("{0:0.00}",1.25 * ammount);
                        break;
                    case "orange":
                        Console.WriteLine("{0:0.00}",0.90 * ammount);
                        break;
                    case "grapefruit":
                        Console.WriteLine("{0:0.00}",1.60 * ammount);
                        break;
                    case "kiwi":
                        Console.WriteLine("{0:0.00}",3.00* ammount);
                        break;
                    case "pineapple":
                        Console.WriteLine("{0:0.00}",5.60 * ammount);
                        break;
                    case "grapes":
                        Console.WriteLine("{0:0.00}",4.20 * ammount);
                        break;
                    default:
                        Console.WriteLine("error");
                        break;
                }
            }
            else if (day == "monday" || day == "tuesday" || day == "wednesday" || day == "thursday" || day == "friday")
            {
                switch (type)
                {
                    case "banana":
                        Console.WriteLine("{0:0.00}",2.50 * ammount);
                        break;
                    case "apple":
                        Console.WriteLine("{0:0.00}",1.20 * ammount);
                        break;
                    case "orange":
                        Console.WriteLine("{0:0.00}",0.85 * ammount);
                        break;
                    case "grapefruit":
                        Console.WriteLine("{0:0.00}",1.45 * ammount);
                        break;
                    case "kiwi":
                        Console.WriteLine("{0:0.00}",2.70 * ammount);
                        break;
                    case "pineapple":
                        Console.WriteLine("{0:0.00}",5.50 * ammount);
                        break;
                    case "grapes":
                        Console.WriteLine("{0:0.00}",3.85 * ammount);
                        break;

                    default:
                        Console.WriteLine("error");
                        break;
                }
            }
            else
            {
                Console.WriteLine("error");
            }
        }
    }
}