<?php 
header('Content-Type: text/html; charset=utf-8');
class open{

    public $file='index.php';
function __wakeup()
{
    $this->file='index.php';

}
function __destruct()
{
   include($this->file);
}
}

if(isset($_GET['open']))
{
    $a=unserialize($_GET['open']);
}
else{
    $b=new open();
}
highlight_file(__FILE__);
// O:4:"open":1:{s:4:"file";s:8:"flag.php";}
?> hello word