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

namespace Example
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Black and white or colour printing: ");
            string printing = Console.ReadLine();
            Console.Write("Number of books: ");
            int numberOfBooks = int.Parse(Console.ReadLine());
            Console.Write("Pages: ");
            int pages = int.Parse(Console.ReadLine());
            double grandTotal = 0;


            switch (printing)
            {
                case "black and white":
                    grandTotal = blackAndWhite(numberOfBooks, pages);
                    break;

                case "colour":
                    grandTotal = colourful(numberOfBooks, pages);
                    break;
            }

            Console.WriteLine($"Grand Total: {grandTotal:f2}");
        }

        public static double blackAndWhite(int numberOfBooks, int pages)
        {
            double priceForASheet = 0.01;
            int plate = 7;
            int priceForBinding = 2;
            double subtotal = (pages * plate) + ((pages / 2) * numberOfBooks) * priceForASheet + numberOfBooks * priceForBinding;
            double vat = subtotal * 0.175;
            double grandTotal = subtotal + vat;
            return grandTotal;
        }

        public static double colourful(int numberOfBooks, int pages)
        {
            double priceForASheet = 0.04;
            double plate = 28;
            double priceForBinding = 2;
            double subtotal = (pages * plate) + ((pages / 2) * numberOfBooks) * priceForASheet + numberOfBooks * priceForBinding;
            double vat = subtotal * 0.175;
            double grandTotal = subtotal + vat;
            return grandTotal;
        }

    }
}