using System;

namespace FruitShop
{
    class Program
    {
        static void Main(string[] args)
        {
            string fruit = Console.ReadLine();
            string day = Console.ReadLine();
            double quantity = double.Parse(Console.ReadLine());
            double price = 0;

            if (day == "Monday" || day == "Tuesday" || day == "Wednesday" || day == "Thursday" || day == "Friday")
            {
                if (fruit == "banana")
                {
                    price = 2.50 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "apple")
                {
                    price = 1.20 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "orange")
                {
                    price = 0.85 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.45 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "kiwi")
                {
                    price = 2.70 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "pineapple")
                {
                    price = 5.5 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "grapes")
                {
                    price = 3.85 * quantity;
					Console.WriteLine($"{price:F2}");
                }
	else
					{
                Console.WriteLine("error");
            }


            }
            // week days:
            //плод    banana  apple orange  grapefruit kiwi    pineapple grapes
            // цена    2.50    1.20    0.85    1.45    2.70    5.50    3.85

            else if (day == "Saturday" || day == "Sunday")
            {
                if (fruit == "banana")
                {
                    price = 2.70 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "apple")
                {
                    price = 1.25 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "orange")
                {
                    price = 0.90 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.60 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "kiwi")
                {
                    price = 3.00 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "pineapple")
                {
                    price = 5.6 * quantity;
					Console.WriteLine($"{price:F2}");
                }
                else if (fruit == "grapes")
                {
                    price = 4.2 * quantity;
					Console.WriteLine($"{price:F2}");
                }
				else
					{
                Console.WriteLine("error");
            }

            }
            else
            {
                Console.WriteLine("error");
            }
            //weekend days:
            //плод banana  apple orange  grapefruit kiwi    pineapple grapes
            // цена    2.70    1.25    0.90    1.60    3.00    5.60    4.20



            //Print: Резултатът да се отпечата закръглен с 2 цифри след десетичната точка.
            //При невалиден ден от седмицата или невалидно име на плод да се отпечата "error".




            }

        }
    }