fruit shop

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _06.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;
            double totalSum = quantity * price;

            if (day == "monday" || day == "tuesday" || day == "wednesday" || day == "friday" || day == "thirsday")
            {
                if (fruit == "banana")
                {
                    price = 2.50;
                }
                else if (fruit == "apple")
                {
                    price = 1.20;
                }
                else if (fruit == "orange")
                {
                    price = 0.85;
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.45;
                }
                else if (fruit == "kiwi")
                {
                    price = 2.70;
                }
                else if (fruit == "pineapple")
                {
                    price = 5.5;
                }
                else if (fruit == "grapes")
                {
                    price = 3.85;
                }
            }
            else if (day == "saturday" || day == "sunday")
            {
                if (fruit == "banana")
                {
                    price = 2.7;
                }
                else if (fruit == "apple")
                {
                    price = 1.25;
                }
                else if (fruit == "orange")
                {
                    price = 0.90;
                }
                else if (fruit == "grapefruit")
                {
                    price = 1.60;
                }
                else if (fruit == "kiwi")
                {
                    price = 3.00;
                }
                else if (fruit == "pineapple")
                {
                    price = 5.60;
                }
                else if (fruit == "grapes")
                {
                    price = 4.20;
                }
            }



            if (totalSum > 0)
            {
                Console.WriteLine($"{totalSum:f2}");
            }
            else
            {
                Console.WriteLine("error");
            }

        }
    }
}