getting error while removing controller and function name in url in codeigniter?

I know this is the most common question, I referred so many questions for that and i successfully removed controller name in URL but after that i can not access my back end(admin panel) OR any other controller because its remove all controller name.

Below is my code in routes.php file

$route['(:any)'] = 'webcontroller/page/$1';
$route['(:num)'] = 'webcontroller/page/$1';
$route['([a-zA-Z0-9]+)'] = "webcontroller/page/$1";

Below is my URL

http://localhost/mysite/webcontroller/page/govtcentral-pressgandhinagar

I am trying to remove webcontroller/page from above URL, But after removing controller and function i can not access below link and give me 404 error.

http://localhost/mysite/bannersmanagement/

Is there any solution for that?