using System;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter a sandwich:");

        Console.WriteLine("1. Chicken $7.50");

        Console.WriteLine("2. Beef $8.50");

        Console.WriteLine("3. Veggie burger $7.75");

​

        int newSand = 0;

        string sandwich = Console.ReadLine();

        bool success = int.TryParse(sandwich, out newSand);

​

        double sandwichPrice = 0.0;

​

        if (success)

        {

            switch (newSand)

            {

                case 1:

                    Console.WriteLine("You selected a Chicken Sandwich!");

                    sandwichPrice = 7.50;

                    break;

                case 2:

                    Console.WriteLine("You selected a Beef Sandwich!");

                    sandwichPrice = 8.50;

                    break;

                case 3:

                    Console.WriteLine("You selected a Veggie Burger!");

                    sandwichPrice = 7.75;

                    break;

                default:

                    Console.WriteLine("Please enter a number 1, 2, or 3");

                    return;

            }

        }

        else

        {

            Console.WriteLine("Enter a valid number (1, 2, or 3) for the sandwich.");

            return;

        }

​

        Console.WriteLine("Do you want a beverage? (yes/no)");

        string beverageChoice = Console.ReadLine().ToLower();

        bool wantsBeverage = beverageChoice == "yes";

​

        string beverageSize = "";

        double beveragePrice = 0.0;

​

        if (wantsBeverage)

        {

            Console.WriteLine("Select your beverage size:");

            Console.WriteLine("1. Small");

            Console.WriteLine("2. Medium");

            Console.WriteLine("3. Large");

​

            int beverageSizeChoice = 0;

            bool beverageSizeParsed = int.TryParse(Console.ReadLine(), out beverageSizeChoice);

​

            if (beverageSizeParsed)

            {

                switch (beverageSizeChoice)

                {

                    case 1:

                        beverageSize = "Small";

                        beveragePrice = 1.50;

                        break;

                    case 2:

                        beverageSize = "Medium";

                        beveragePrice = 2.00;

                        break;

                    case 3:

                        beverageSize = "Large";

                        beveragePrice = 2.50;

                        break;

                    default:

                        Console.WriteLine("Invalid beverage size selected.");

                        return;

                }

            }

            else

            {

                Console.WriteLine("Enter a valid number (1, 2, or 3) for the beverage size.");

                return;

            }

        }

​

        Console.WriteLine("Do you want fries? (yes/no)");

        string friesChoice = Console.ReadLine().ToLower();

        bool wantsFries = friesChoice == "yes";

​

        double friesPrice = 0.0;

        bool megaSizeFries = false;

​

        if (wantsFries)

        {

            Console.WriteLine("Select your fries size:");

            Console.WriteLine("1. Small $1.50");

            Console.WriteLine("2. Medium $2.00");

            Console.WriteLine("3. Large $2.50");

​

            int friesSizeChoice = 0;

            bool friesSizeParsed = int.TryParse(Console.ReadLine(), out friesSizeChoice);

​

            if (friesSizeParsed)

            {

                switch (friesSizeChoice)

                {

                    case 1:

                        friesPrice = 1.50;

                        Console.WriteLine("Do you want to mega-size your fries? (yes/no)");

                        string megaSizeChoice = Console.ReadLine().ToLower();

                        megaSizeFries = megaSizeChoice == "yes";

                        break;

                    case 2:

                        friesPrice = 2.00;

                        break;

                    case 3:

                        friesPrice = 2.50;

                        break;

                    default:

                        Console.WriteLine("Invalid fries size selected.");

                        return;

                }

            }

            else

            {

                Console.WriteLine("Enter a valid number (1, 2, or 3) for the fries size.");

                return;

            }

        }

​

        double totalCost = sandwichPrice + beveragePrice + friesPrice;

​

        if (wantsFries && wantsBeverage && success)

        {

            totalCost -= 1.00;

        }

​

        Console.Write("Enter the amount you want to pay: $");

        double paymentAmount = 0.0;

        bool paymentParsed = double.TryParse(Console.ReadLine(), out paymentAmount);

​

        if (!paymentParsed)

        {

            Console.WriteLine("Invalid payment amount entered.");

            return;

        }

​

        double change = paymentAmount - totalCost;

​

        Console.WriteLine("Receipt:");

        Console.WriteLine("-----------------------------------------------------");

        Console.WriteLine($"Sandwich: {sandwichPrice:C}");

        Console.WriteLine("-----------------------------------------------------");

        if (wantsBeverage)

        {

            Console.WriteLine($"Beverage ({beverageSize}): {beveragePrice:C}");

            Console.WriteLine("-----------------------------------------------------");

        }

        if (wantsFries)

        {

            if (megaSizeFries)

            {

                Console.WriteLine("Fries (Mega-sized): $2.50");

                Console.WriteLine("-----------------------------------------------------");

            }

            else

            {

                Console.WriteLine($"Fries: {friesPrice:C}");

                Console.WriteLine("-----------------------------------------------------");

            }

        }

        Console.WriteLine("-----------------------------------------------------");

        Console.WriteLine($"Total cost: {totalCost:C}");

        Console.WriteLine("-----------------------------------------------------");

        Console.WriteLine($"Discount applied: {(wantsFries && wantsBeverage && success ? "$1.00" : "None")}");

        Console.WriteLine("-----------------------------------------------------");

        Console.WriteLine($"Payment: ${paymentAmount:C}");

        Console.WriteLine("-----------------------------------------------------");

        Console.WriteLine($"Change: ${change:C}");

        Console.WriteLine("-----------------------------------------------------");

    }

}

​