//No database is connected. Variables are stored in memory at runtime
using System;

namespace ConsoleApp1
{
    internal class Program
    {
    		//variables are created globally. coz need to use in multiple methods.
        static string userName, password;
        
        public static void Main(string[] args)
        {
            Register();
            Login();   
        }

        //register()
        public static void Register() {
            Console.WriteLine("---------- Registration ---------");
            Console.WriteLine("User name: ");
            userName = Console.ReadLine();
            Console.WriteLine("Password: ");
            password = Console.ReadLine();
            Console.WriteLine("Registration successfull");
            Console.WriteLine();
        }

        //login
        public static void Login() {
            Console.WriteLine("User name: ");

            if (userName == Console.ReadLine())
            {
                Console.WriteLine("Password: ");

                if (password == Console.ReadLine())
                {
                    Console.WriteLine("Login Successful");
                }
                else 
                {
                    Console.WriteLine("Invalid Password");
                }
            }
            else 
            {
                Console.WriteLine("Invalid User name !");
            }
        }
    }
}