How to to static function from Helper Laravel?

I have custom class in path:

app/Http/Helpers/Helper/Helper.php 

with namespace is: namespace App\Helpers;

It has a static method:

 public
    static function getMonthName($monthNumber)
    {
        return date("F", mktime(0, 0, 0, $monthNumber, 1));
    }

I tried to call this method from template Laravel:

But it does not work:

Class 'App\Http\Helpers\Helper' not found

via Chebli Mohamed