using System;

using System.Collections;

using System.Collections.Generic;

​

public class MainClass {

  public static void Main (string[] args) {

    ArrayList name = new ArrayList();

    List<long> contactnum = new List<long>();

    bool loop = true;

​

    while (loop) 

    {

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

      Console.WriteLine("\n[1] Create New Contact");

      Console.WriteLine("[2] View all Contacts");

      Console.WriteLine("[3] Exit Application");

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

      string choice = Console.ReadLine();

​

      switch(choice)

      {

        case "1":

        Console.WriteLine("\n-----CREATE NEW CONTACT-----");

        Console.WriteLine("Name: ");

        name.Add(Console.ReadLine());

        Console.WriteLine("Contact number: ");

        long number = Convert.ToInt64(Console.ReadLine());

        contactnum.Add(number);

        Console.WriteLine("New contact added. \n");

        continue;

​

        case "2":

        Console.WriteLine("-------LIST OF CONTACTS-------\n");

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

        for(int a = 0, size = name.Count; a < size; a++)

        {

          Console.WriteLine(name + "      " + contactnum);

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

        }

        Console.WriteLine("\n");

        break;

​

        case "3":

        Console.WriteLine("\nPhone book closed.");

        loop = false;

        break;

​

        default:

        Console.WriteLine("\nInvalid input. Please try again.");

        continue;

      }

    }

  }

}