using System;

using System.Linq;

​

namespace Billing

{

    public class Program

    {

        public static void Main(string[] args)

        {

            double CustomerAmount = 20;  // change the customer amount 

            double ProductPrice = 5.50;  // change the product amount 

            double BlanceAmount = CustomerAmount >= ProductPrice ? (CustomerAmount - ProductPrice) : 0.00;

            if (BlanceAmount > 0)

            {

                int[] Denominations = {50, 40, 20, 10, 2, 1};

                double Value = 0.00;

                int LastVal = Denominations.Last();

                Console.WriteLine("Your Change is:");

                foreach (int item in Denominations)

                {

                    if (BlanceAmount > item)

                    {

                        Value = (int)BlanceAmount / item;

                        BlanceAmount = BlanceAmount % item;

                        Console.WriteLine($"{Value} x £{item}");

                    }

​

                    if (LastVal == item && BlanceAmount != 0)

                    {

                        Console.WriteLine($"1 x {string.Format("{0:f2}", BlanceAmount).Remove(0, 2)}p");

                    }

                }

            }

            else

            {

                Console.WriteLine("Please provide a valid CustomerAmount...");

            }

        }

    }

}