After installed Symfony2 it is showing 404 when I access app.php?

In Symfony2, when i run my application locally on app_dev.php, everything works fine. However, when I access app.php it shows the error

Oops! An Error Occurred
The server returned a "404 Not Found".
Something is broken. Please e-mail us at [email] and let us know what you were doing when this error occurred. We will fix it as soon as possible. Sorry for

I figured out and found a simple solution.
May this will work for you.

just open your src\AppBundle\Controller\DefaultController.php

Then you can see there in file for Home router
/**
   * @Route("/app/example", name="homepage")
*/

So the error is due to this route

just change it like this

/**
     * @Route("/", name="homepage")
*/

Then go to the cache folder app\cache
delete the prod folder then refresh the page