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 fruits = Console.ReadLine().ToLower();
                string dayOfWeek = Console.ReadLine().ToLower();
                double quantity = double.Parse(Console.ReadLine());

                double price = 0;


                if (dayOfWeek == "monday" || dayOfWeek == "tuesday" || dayOfWeek == "wednesday" || dayOfWeek == "thursday" ||
                    dayOfWeek == "friday")
                {
                    if (fruits == "banana") price = 2.50;
                    {
                        price = 2.50 * quantity;
                        if (price >= 0)
                        {
                            Console.WriteLine("{0:f2}", price * quantity);
                        }
                    }
                }

                else if (fruits == "apple") price = 1.20;
                {
                    price = 1.20 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }


                else if (fruits == "orange") price = 0.85;
                {
                    price = 0.85 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }

                else if (fruits == "grapefruit") price = 1.45;
                {
                    price = 1.45 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }


                else if (fruits == "kiwi") price = 2.70;
                {
                    price = 2.70 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }
                else if (fruits == "pineapple") price = 5.50;
                {
                    price = 5.50 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }
                else if (fruits == "grapes") price = 3.85;
                {
                    price = 3.85 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                    else
                    {
                        Console.WriteLine("error");
                    }
                }

            else if (dayOfWeek == "saturday" || dayOfWeek == "sunday")
                {
                    if (fruits == "banana") price = 2.70;
                    {
                        price = 2.70 * quantity;
                        if (price >= 0)
                        {
                            Console.WriteLine("{0:f2}", price * quantity);
                        }

                    }
                }

                else if (fruits == "apple") price = 1.25;
                {
                    price = 1.25 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }
                else if (fruits == "orange") price = 0.90;
                {
                    price = 0.90 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }

                else if (fruits == "grapefruit") price = 1.60;
                {
                    price = 1.60 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }

                else if (fruits == "kiwi") price = 3.00;
                {
                    price = 3.00 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }

                else if (fruits == "pineapple") price = 5.60;
                {
                    price = 5.60 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }

                else if (fruits == "grapes") price = 4.20;
                {
                    price = 4.20 * quantity;
                    if (price >= 0)
                    {
                        Console.WriteLine("{0:f2}", price * quantity);
                    }
                }
                else
                {
                    Console.WriteLine("error");
                }
            }

            else
            {
                Console.WriteLine("error");
            }
            Console.WriteLine($"{Math.Round(price, 2)}");
        }
    }
}