title: How to create my_Controller in sub directory for core and library in Codeigniter3?
body: <p>How to create my_Controller in sub directory for core and library in Codeigniter?
  I want to create sub director for admin pages using Codeigniter3
  as below requirement.</p>
  
  <p>Controller/admin/Admin_C <strong>(Exstend Admin_Controller)</strong> 1</p>
  
  <p>Library/admin/Admin_Controller <strong>(extends Cadmin_Controller)</strong> 2</p>
  
  <p>Core/admin/Cadmin_Controller <strong>(extends CI_Controllers)</strong> 3</p>
  
  <p><strong>Problem</strong>   <code>Fatal error: Class 'Admin_Controller' not found in D:\My data\project\wamp\www\Cootel\application\controllers\admin\Admin_C.php on line 3</code></p>
  
  <p><img src="https://i.stack.imgur.com/bJngl.png" alt="enter image description here"></p>