using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication3
{
  class Program
  {
    static void Main(string[] args)
    {
      /*
      string[] weekdays = new string[7];
      // string[] week = new string[] { "Sunday", "Monday", "Tuesday" };
      weekdays[0] = "monday";
      weekdays[1] = "tuesday";
      weekdays[2] = "wednesday";
      weekdays[3] = "thursday";
      weekdays[4] = "friday";
      weekdays[5] = "saturday";
      weekdays[6] = "sunday";

      for (int i = 0; i < weekdays.Length; i++)
      {
        Console.WriteLine(weekdays[i]);
      }
      */

      // default data
      string systemUsername = "john";
      string[] systemUsernames = new string[] { "user1", "user2" };
      string systemPassword = "doe";
      string[] systemPasswords = new string[] { "asdasd", "qweqwe" };

      string username = "";
      string password = "";
      bool validCredentials = false;

      // Welcome screen
      Console.WriteLine("Welcome to our system");

      while (validCredentials == false)
      {
        Console.WriteLine("Enter username:");
        username = Console.ReadLine();
        Console.WriteLine("Enter password:");
        password = Console.ReadLine();

        for (int i = 0; i < systemUsernames.Length; i++)
        {

          if (username == systemUsernames[i])
          {
            if (password == systemPasswords[i])
            {
              validCredentials = true;
              Console.WriteLine("Welcome to the system!");
            }
            else
            {
              Console.WriteLine("Incorrect password!");
            }
          }
        }
      }

      // system pause // press key to exit
      Console.ReadKey();
    }
  }
}