using System;

public class Program

{

    public static void Main()

    {

        while (true)

            {

                string[] coffees = { "Latte", "Americano", "Espresso", "Capuccino" };

                for (int i = 1; i < coffees.Length+1; i++)

                {

                    Console.WriteLine(i + "." + coffees[i-1] + " : " + i * 100 + " DRAM");

                }

                Console.Write("\n" + "Insert your money: ");

                int insertedMoney = Convert.ToInt32(Console.ReadLine());

                if (insertedMoney%50 !=0)

                {

                    Console.WriteLine("Wrong input, try again! \n ");

                    continue;

                }

                bool notEnoughMoney = true;

                Console.Write("Choose the number of the coffee: ");

                int choice = Convert.ToInt32(Console.ReadLine());

                int coffeePrice = 0;

                Console.WriteLine();

                if (choice > 0 && choice <= 4)

                {

                    coffeePrice = choice * 100;

                }

                else

                {

                    Console.WriteLine("Wrong input, try again");

                    continue;

                }

                while (notEnoughMoney)

                {

                    if (insertedMoney == coffeePrice)

                    {

                        notEnoughMoney = false;

                    }

                    else if (insertedMoney < coffeePrice)

                    {

                        int toBeAdded = coffeePrice - insertedMoney;

                        Console.WriteLine("Please add " + toBeAdded + " DRAM");

                        int moreinsert = Convert.ToInt32(Console.ReadLine());

                        if(moreinsert % 50 != 0) 

                        {

                            Console.WriteLine("Wrong input, try again!");

                            continue;

                        }

                        insertedMoney += moreinsert;

                    }

                    else if (insertedMoney > coffeePrice)

                    {

                        int c = insertedMoney - coffeePrice;

                        Console.WriteLine("Your change of " + c + " DRAM will be yielded");

                        notEnoughMoney = false;

                    }

                }

                Console.WriteLine();

                Console.Write("Choose the amount of sugar in your coffee: ");

                int sugarAmount = Convert.ToInt32(Console.ReadLine());

                AddSugar(sugarAmount);

                int change = insertedMoney - coffeePrice;

                if (change > 0)

                {

                    ChangeDenomination(change);

                }

                Console.WriteLine("\n" + "********************************" + "\n");

            }

​

        }

        static void AddSugar(int amount)

        {

           for (int i = 0; i < amount; i++)

            {

                Console.WriteLine("a teaspoon of sugar added");

            }

            Console.WriteLine();

        }

        static void ChangeDenomination(int change) 

        {

            int[] changes = { 500, 200, 100,50 };

            int c = 0;

            bool notDone = true;

            while (notDone)

            {

                if (change >= changes[c])

                {

                    for (int i = 0; i < change/changes[c]; i++)

                    {

                        Console.WriteLine(changes[c]);

                        change -= changes[c];

                    }

                }

                else if (change <= 0) 

                {

                    notDone = false;

                }

                else 

                {

                    c++;

                }

            }

    }

}