using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("請輸入使用者名稱");

        string username,password;

        username=Console.ReadLine();

        if(username=="馬壯")

        {

            Console.WriteLine(username+"您好");

        }

        else if(username=="徐強")

        {

            Console.WriteLine(username+"您好");

        }

        else

        {

            Console.WriteLine("本系統不認識"+username);

        }

        Console.WriteLine("請輸入密碼:");

            password=Console.ReadLine();

        if(username=="馬壯")

            if((password=="egg566")||

               (password=="EGG566"))

            {

                Console.WriteLine("歡迎進入本系統");

            }

            else

               {

                   Console.WriteLine("密碼錯誤");

               }

        if(username=="徐強")

            if((password=="dog123")||

               (password=="Dog123"))

            {

                Console.WriteLine("歡迎進入本系統");

            }

        else

        {

            Console.WriteLine("密碼錯誤");

        }

    }

}

​