using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        bool exit = false;

        while (exit == false)

        {

            Console.WriteLine("What snack would you like to purchase?");

            Console.WriteLine();

            Console.WriteLine("[1] Cheez-Its (13 Servings)");

            Console.WriteLine("[2] Oreos (16 servings)");

            Console.WriteLine("[3] Pistachios (9 servings)");

            Console.WriteLine("[4] Bunny Grahams (6 servings)");

            Console.WriteLine("[0] Exit");

            string choice = Console.ReadLine();

            if (choice == "1")

            {

                // cheezit stuff

            }

            else if (choice == "2")

            {

                //oreo stuff

            }

            else if (choice == "3")

            {

                // pistachio stuff

            }

            else if (choice == "4")

            {

                // bunny stuff

            }

            else

            {

                goto Exit;

            }

            Exit:

                exit = true;

        }

    }

}

​

public abstract class Snack

{

    public int Servings { get; set; }

    public int Quantity { get; set; }

    public abstract int GetServings();

​

}

​

public class CheezIt : Snack

{

    public CheezIt(int quantity)

    {

        Servings = 13;

        Quantity = quantity;

    }

    public override int GetServings()

    {

        return Servings*Quantity;

    }

}

​

public class Oreo : Snack

{

    public Oreo(int quantity)

    {

        Servings = 16;

        Quantity = quantity;

    }

    public override int GetServings()

    {

        return Servings*Quantity;

    }

}

​

public class Pistachio : Snack

{

    public Pistachio(int quantity)

    {

        Servings = 9;

        Quantity = quantity;

    }

    public override int GetServings()

    {

        return Servings*Quantity;

    }

}

​

public class Bunny : Snack

{

    public Bunny(int quantity)

    {

        Servings = 6;

        Quantity = quantity;

    }

    public override int GetServings()

    {

        return Servings*Quantity;

    }

}

​

public class Pantry

{

    private List<Snack> Snacks = new List<Snack>();

    public void AddSnack(Snack snack)

    {

        Snacks.Add(snack);

    }

    public void EatSnack(Snack snack)

    {

        Snacks.Remove(snack);

    }

    public int ServingsInPantry()

    {

        int servings = 0;

        for (int i = 0; i < Snacks.Count; i++)

        {

            servings += Snacks[i].GetServings();

        }

        return servings;

    }

}