using System;

namespace storeForFruits
{
    class Program
    {
        static void Main(string[] args)
        {
            string fruit = Console.ReadLine();
            string day = Console.ReadLine();
            double quantity = double.Parse(Console.ReadLine());
            double price = 0.00;

            if (day == "Monday" || day == "Tuesday" || day == "Wednesday" || day == "Thursday" || day == "Friday")
            {
                if (fruit == "banana")
                {
                    price = 2.50;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "apple")
                {
                    price = 1.20;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "orange")
                {
                    price = 0.85;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.45;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "kiwi")
                {
                    price = 2.70;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "pineapple")
                {
                    price = 5.50;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "grapes")
                {
                    price = 3.85;
 Console.WriteLine($"{price * quantity:f2}");
                }
				else {
					Console.WriteLine("error");
				}

            }
            else if (day == "Saturday" || day == "Sunday")
            {
                if (fruit == "banana")
                {
                    price = 2.70;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "apple")
                {
                    price = 1.25;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "orange")
                {
                    price = 0.90;
 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.60;
					 Console.WriteLine($"{price * quantity:f2}");
                }
                else if (fruit == "kiwi")
                {
                   Console.WriteLine($"{3.00 * quantity:f2}");
                }
                else if (fruit == "pineapple")
                {
                  Console.WriteLine($"{5.60 * quantity:f2}");
                }
                else if (fruit == "grapes")
                {
                Console.WriteLine($"{4.20 * quantity:f2}");
				}
				else {
					Console.WriteLine("error");
				}


            }
			else {
					Console.WriteLine("error");
			}

            }
        }
    }