Simple calculator in PHP utilizing MVC

I have been struggling with understanding Model, View, Service, Controller architecture and wrote some code.

• Is my Model class the Model part of MVC (did I define it properly)?
• Is my Service class a Service Layer (did I define the layer properly)?
• Did I connect my layers properly (is the 'wiring' set up correctly)?

 /*
 * Application Idea:  Assume UI has two input boxes and a button and an output box
 * box A is for a number
 * box B is for a number
 * 
 * event of a button click sends responce of (A+B) into the output button
 * Implement Controller, Service, Model, View layers
 */
class Controller
{

    /**
     *
     * @var Service
     */
    private $service;

    /**
     *
     * @var Model
     */
    private $model;

    // add A B update C for all
    function addAB()
    {
        $a = $this->model->getA();
        $b = $this->model->getB();

        $c = $this->service->computeSum($a, $b);
        $this->model->setC($c);

        $view = new View();
        return $view->render($a, $b, $c);
    }

    public function getService()
    {
        return $this->service;
    }

    public function setService($service)
    {
        $this->service = $service;
    }

    public function getModel()
    {
        return $this->model;
    }

    public function setModel($model)
    {
        $this->model = $model;
    }
}

class ControllerFactory
{

    function getController(array $request)
    {
        $model = new Model();
        $model->setA($request['a']);
        $model->setB($request['b']);

        $service = new Service();

        $controller = new Controller();
        $controller->setService($service);
        $controller->setModel($model);

        return $controller;
    }
}

class Model
{

    private $a;

    private $b;

    private $c;

    public function getA()
    {
        return $this->a;
    }

    public function getB()
    {
        return $this->b;
    }

    public function getC()
    {
        return $this->c;
    }

    public function setA($a)
    {
        $this->a = $a;
    }

    public function setB($b)
    {
        $this->b = $b;
    }

    public function setC($c)
    {
        $this->c = $c;
    }
}

class Service
{

    function computeSum($a, $b)
    {
        return $a + $b;
    }
}

class View
{

    function render($a, $b, $c)
    {
        print "$a + $b = $c";
    }
}

class Router
{

    function routeRequest($request)
    {
        $controller = (new ControllerFactory())->getController($request);
        switch ($request['event'])
        {
            case 'add_event':
                $controller->addAB();
                break;
        }
    }
}

/*
 * request can come from Web Browser
 */
$request = array();
$request['event'] = "add_event";
$request['a'] = 2;
$request['b'] = 3;

$router = new Router();
$router->routeRequest($request);