Laravel5中的最后一个插入ID

laravel 5 How do I download the latest id added to the model? It's simple, I have a form that sends data via post to:

route:
    Route::get('/insert/{data}', 'IdataController@ins');
    Route::post('/insert/{data}', 'IdataController@add_data');
controller:

    public function ins($data = 1){


        if($data == 1){
//display data
        }elseif($data == 2){
// this place I need last insert id

        }



    }
    public function add_data(Request $request, $data){

        if($data == 1){
            $r = $this->insert_my([
                'name'=>$request->name,
                'relationid'=>$request->relationid
            ]);
            return $r;
        }else($data ==2){
//next operations
}

    }
    private function insert_my($data){

        $r=  Insertmodel::create([
            'name'=>$data['name'],
            'relationid'=>$data['relationid']
        ]);

        return Redirect::to('insert/2');
    }

The best solution for me is to download last id from Model. But how to do it ?

id needs to get in this place:

elseif($data == 2){
    // this place I need last insert id

            }

try

update

$data = Model::all()->last()->id; 

or

$data = Model::orderby('created_at')->first();

then $data->id

You can retrieve it this way:

private function insert_my($data){

    $r=  Insertmodel::create([
        'name'=>$data['name'],
        'relationid'=>$data['relationid']
    ]);

    return Redirect::to('insert/2?id='. $r->id);
}

Once you redirect, it will be available in the controller as $request->id.