Multi Module Sub Controllers

Project Structure:

|---- app
|     |---- controllers
|     |     |---- admin
|     |     |     |---- IndexController.php
|     |     |---- IndexController.php
|     |---- modules
|     |     |---- slideshow
|     |     |     |---- controllers
|     |     |     |     |---- admin
|     |     |     |     |     |---- IndexController.php
|     |     |     |     |---- IndexController.php
|     |     |     |---- Module.php

My question is about the routing. Currently, this is what I want to achieve.

<?php

//admin
$router->add('/admin/:module/:controller', [
    'module'    => 1,
    'controller' => 2 // src: app/modules/slideshow/controllers/admin/IndexController.php
]);

//public
$router->add('/page/:module/:controler', [
    'module'    => 1,
    'controller' => 2 // src: app/modules/slideshow/controllers/IndexController.php
]);

I want to route all admin specific controllers from that module, WHILE keeping non-admin specific controllers to route to public routes. Please let me know if I made myself clear. Thanks a bunch!