using System;

namespace _11._Fruit_Shop
{
	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;
			bool isError = false;

			if (day == "Monday" || day == "Tuesday" || day == "Wednesday" || day == "Thursday" || day == "Friday")
			{
				switch (fruit)
				{
					case "banana":
						price = quantity * 2.50;
						break;
					case "apple":
						price = quantity * 1.20;
						break;
					case "orange":
						price = quantity * 0.85;
						break;
					case "grapefruit":
						price = quantity * 1.45;
						break;
					case "kiwi":
						price = quantity * 2.70;
						break;
					case "pineapple":
						price = quantity * 5.50;
						break;
					case "grapes":
						price = quantity * 3.85;
						break;

					default:
						Console.WriteLine("error");
						isError = true;
						break;
				}

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

			}
			else
			{
				Console.WriteLine("error");
				isError = true;
			}

			if (!isError)
			{
				Console.WriteLine($"{price:F2}");
			}

		}
	}
}