using System;

namespace Fruit_Shop
{
    class Program
    {
        static void Main(string[] args)
        {
            string fruit = Console.ReadLine();
            string day = Console.ReadLine().ToLower();
            var quantity = double.Parse(Console.ReadLine());
            var price = 0.0;

            if (day == "saturday" || day == "sunday")
            {
                if (fruit == "banana")
                {
                  price = 2.70;
                  Console.WriteLine("{0:f2}", price * quantity);
                }
                  else if (fruit == "apple")
              {
                price = 1.25;
                Console.WriteLine("{0:f2}", price * quantity);
              }
              else if (fruit == "orange") {
                price = 0.90;
                 Console.WriteLine("{0:f2}", price * quantity);
              }
              else if (fruit == "grapefruit")
              {
                price = 1.60;
                 Console.WriteLine("{0:f2}", price * quantity);
              }
                else if (fruit == "kiwi")
                {
                  price = 3.00;
                 Console.WriteLine("{0:f2}", price * quantity);
                }
                  else if (fruit == "pineapple")
                  {
                    price = 5.60;
                Console.WriteLine("{0:f2}", price * quantity);
                  }
                    else if (fruit == "grapes")
                    {
                      price = 4.20;
                Console.WriteLine("{0:f2}", price * quantity);
                    }
              else
              {
                Console.WriteLine("error");
              }
            }

            else if (day == "monday" || day == "tuesday" || day == "wednesday" || day == "thursday" || day == "friday")
            {
                if (fruit == "banana")
                {
                 price = 2.50;
                 Console.WriteLine("{0:f2}", price * quantity);
                }
                else if (fruit == "apple")
                  {
                  price = 1.20;
                  Console.WriteLine("{0:f2}", price * quantity);
                  }
                else if (fruit == "orange")
                {
                 price = 0.85;
                 Console.WriteLine("{0:f2}", price * quantity);
                }
                 else if (fruit == "grapefruit")
                 {
                   price = 1.45;
                   Console.WriteLine("{0:f2}", price * quantity);
                 }
                else if (fruit == "kiwi")
                {
                  price = 2.70;
                  Console.WriteLine("{0:f2}", price * quantity);
                }
                else if (fruit == "pineapple")
                {
                  price = 5.50;
                  Console.WriteLine("{0:f2}", price * quantity);
                }
                else if (fruit == "grapes")
                {
                  price = 3.85;
                   Console.WriteLine("{0:f2}", price * quantity);
                }
               else
               {
                 Console.WriteLine("error");
               }
            }
            else
            {
                Console.WriteLine("error");
            }

            Console.ReadLine();
        }
    }
}