FruitShop

namespace FruitShop
{
    using System;

    class FruitShop
    {
        static void Main()
        {
            var fruit = Console.ReadLine().ToLower();
            var day = Console.ReadLine().ToLower();
            var qty = double.Parse(Console.ReadLine());

            var price = 0.0;

            if (!(day == "monday" || day == "tuesday" || day == "wednesday" || day == "thursday" || day == "friday" || day == "saturday" || day == "sunday"))
            {
                Console.WriteLine("error");
                return;
            }

            if (!(fruit == "banana" || fruit == "apple" || fruit == "orange" || fruit == "grapefruit" || fruit == "kiwi" || fruit == "pineapple" || fruit == "grapes"))
            {
                Console.WriteLine("error");
                return;
            }

            if (day == "saturday" || day == "sunday")
            {
                if (fruit == "banana")
                {
                    price = 2.70;
                }
                else if (fruit == "apple")
                {
                    price = 1.25;
                }
                else if (fruit == "orange")
                {
                    price = 0.9;
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.6;
                }
                else if (fruit == "kiwi")
                {
                    price = 3.0;
                }
                else if (fruit == "pineapple")
                {
                    price = 5.6;
                }
                else if (fruit == "grapes")
                {
                    price = 4.2;
                }
            }
            else
            {
                if (fruit == "banana")
                {
                    price = 2.5;
                }
                else if (fruit == "apple")
                {
                    price = 1.2;
                }
                else if (fruit == "orange")
                {
                    price = 0.85;
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.45;
                }
                else if (fruit == "kiwi")
                {
                    price = 2.7;
                }
                else if (fruit == "pineapple")
                {
                    price = 5.5;
                }
                else if (fruit == "grapes")
                {
                    price = 3.85;
                }
            }


            Console.WriteLine(Math.Round(price * qty, 2));
        }
    }
}