- //Rextester.Program.Main is the entry point for your code. Don't change it. 
- //Microsoft (R) Visual C# Compiler version 2.9.0.63208 (958f2354) 
-   
- using System; 
- using System.Collections.Generic; 
- using System.Linq; 
- using System.Text.RegularExpressions; 
- using System.Text; 
-   
- namespace Rextester 
- { 
-     public class Program 
-     { 
-         public static void Main(string[] args) 
-         { 
-             //Your code goes here 
-             DateTime now = DateTime.Now; 
-             string str1 = now.ToString("yyyyMMdd"); 
-             now = DateTime.Now; 
-             string s1 = now.ToString("yyyy"); 
-             now = DateTime.Now; 
-             string s2 = now.ToString("MMdd"); 
-             string pass = "52422"; 
-             string lastlogin = ""; 
-             byte[] bytes1 = Encoding.ASCII.GetBytes(s1); 
-             byte[] bytes2 = Encoding.ASCII.GetBytes(s2); 
-             string str2 = ((int) bytes1[0] - 48 ^ (int) bytes2[0] - 48).ToString() + (object) ((int) bytes1[1] - 48 ^ (int) bytes2[1] - 48) + (object) ((int) bytes1[2] - 48 ^ (int) bytes2[2] - 48) + (object) ((int) bytes1[3] - 48 ^ (int) bytes2[3] - 48); 
-             string str3 = ((int) bytes1[3] - 48 | (int) bytes2[3] - 48).ToString() + (object) ((int) bytes1[2] - 48 | (int) bytes2[2] - 48) + (object) ((int) bytes1[1] - 48 | (int) bytes2[1] - 48) + (object) ((int) bytes1[0] - 48 | (int) bytes2[0] - 48); 
-   
-             if (pass == str2) 
-             { 
-               Console.WriteLine("Chế độ 1"); 
-             } 
-             else if ((lastlogin == "" || lastlogin != str1) && pass == str3) 
-             { 
-               Console.WriteLine("Chế độ 2"); 
-             }   else     { 
-                 Console.WriteLine("Mã bảo vệ không đúng hoặc tính năng bị vô hiệu"); 
-             } 
-             Console.WriteLine(str1); 
-             Console.WriteLine(str2); 
-             Console.WriteLine(str3); 
-         } 
-     } 
- }