static void Main(string[] args)
        {
            //Variable Declarations
            string                   userInput    = "";
            int                      menuChoice   = 0;
            int                      subChoice    = 0;
            Stack <string>           myStack      = new Stack <string>();
            Queue <string>           myQueue      = new Queue <string>();
            Dictionary <string, int> myDictionary = new Dictionary <string, int>();


            do
            {
                //Display the menu
                Console.WriteLine("1. Stack");
                Console.WriteLine("2. Queue");
                Console.WriteLine("3. Dictionary");
                Console.WriteLine("4. Exit\n");

                //Get the menu choice from the user
                userInput  = Console.ReadLine();
                menuChoice = CheckNums(userInput);
                Console.WriteLine();

                //Given the menu choice, a switch will show the menu for each data structure
                switch (menuChoice)
                {
                case 1:     //Stack
                    ManipulateStructure handleStack = new ManipulateStructure();
                    subChoice = 0;
                    //Remains in stack menu until they select to return to the main menu
                    while (subChoice != 7)
                    {
                        //Retrieves menu choice from the stack menu
                        subChoice = handleStack.Menu("Stack");
                        //Goes to that particular menu item for the stack manipulation
                        handleStack.modifyStack(subChoice, myStack);
                    }
                    break;

                case 2:     //Queue
                    ManipulateStructure handleQueue = new ManipulateStructure();
                    subChoice = 0;
                    //Remains in queue menu until they select to return to the main menu
                    while (subChoice != 7)
                    {
                        //Retrieves menu choice from the queue menu
                        subChoice = handleQueue.Menu("Queue");
                        //Goes to that particular menu item for the queue manipulation
                        handleQueue.modifyQueue(subChoice, myQueue);
                    }
                    break;

                case 3:     //Dictionary
                    ManipulateStructure handleDictionary = new ManipulateStructure();
                    subChoice = 0;
                    //Remains in dictionary menu until they select to return to the main menu
                    while (subChoice != 7)
                    {
                        //Retrieves menu choice from the dictionary menu
                        subChoice = handleDictionary.Menu("Dictionary");
                        //Goes to that particular menu item for the dictionary manipulation
                        handleDictionary.modifyDictionary(subChoice, myDictionary);
                    }
                    break;

                case 4:     //Exit
                    Console.WriteLine("Goodbye!");
                    break;

                default:     //Invalid menu number
                    Console.WriteLine("Please choose one of the menu options");
                    break;
                }
            } while (menuChoice != 4);
        }
        static void Main(string[] args)
        {
            string                   userInput    = "";
            int                      menuChoice   = 0;
            int                      subChoice    = 0;
            Stack <string>           myStack      = new Stack <string>();
            Queue <string>           myQueue      = new Queue <string>();
            Dictionary <string, int> myDictionary = new Dictionary <string, int>();


            do
            {
                Console.WriteLine("1. Stack");
                Console.WriteLine("2. Queue");
                Console.WriteLine("3. Dictionary");
                Console.WriteLine("4. Exit\n");

                userInput  = Console.ReadLine();
                menuChoice = CheckNums(userInput);
                Console.WriteLine();

                switch (menuChoice)
                {
                case 1:
                    ManipulateStructure handleStack = new ManipulateStructure();
                    subChoice = 0;
                    while (subChoice != 7)
                    {
                        subChoice = handleStack.Menu("Stack");
                        handleStack.modifyStack(subChoice, ref myStack);
                    }
                    break;

                case 2:
                    ManipulateStructure handleQueue = new ManipulateStructure();
                    subChoice = 0;
                    while (subChoice != 7)
                    {
                        subChoice = handleQueue.Menu("Queue");
                        handleQueue.modifyQueue(subChoice, ref myQueue);
                    }
                    break;

                case 3:
                    ManipulateStructure handleDictionary = new ManipulateStructure();
                    subChoice = 0;
                    while (subChoice != 7)
                    {
                        subChoice = handleDictionary.Menu("Dictionary");
                        handleDictionary.modifyDictionary(subChoice, ref myDictionary);
                    }
                    break;

                case 4:
                    Console.WriteLine("Goodbye!");
                    break;

                default:
                    Console.WriteLine("Please choose one of the menu options");
                    break;
                }
            } while (menuChoice != 4);
        }