Divide
======

Let's consider a non-empty list of :class:`int` numbers. We want to process the numbers up to a given number (this let's call it the *mark*) and separate these numbers into 2 lists: one list with the numbers above or equal than the average of all numbers in the given list, and another with the ones under the average.
If the mark is not found in the list then all numbers will be processed.
Moreover both lists must additionally have at the end a :class:`float` number corresponding to the average of its values, rounded to 1 decimal.

Implement the following Python functions in the module :mod:`divide` (file :file:`divide.py`). Starting with the second one is recommended.

The first function is:

    ``divide(ln, mark)``
        | takes  ``ln`` a non-empty list of :class:`int`, and ``mark`` an arbritary  :class:`int`.
        | returns 2 lists of :class:`int` according to the description above.

For exemple:

   .. literalinclude:: divide-test.txt
      :language: python3
      :lines: 3-
      
Doctests are available at the :download:`divide-test.txt` file.

This function **must** call the following function:

    ``add_avg(ln)``
        | takes ``ln`` a (might be empty) list of :class:`int`.
        | **modifies**  ``ln`` by adding the average of its values at the end (must be a :class:`float` rounded to 1 decimal).

For exemple:

   .. literalinclude:: add_avg-test.txt
      :language: python3
      :lines: 3-

Doctests are available at the :download:`add_avg-test.txt` file.