Offices (2 points)
==================

A company is conducting a study of the occupancy of its offices. The
corresponding data is stored in a nested :class:`list`. Each sublist
of it corresponds to a floor of the company building and consists of a
first item with the name of the floor (:class:`str`) and a variable
number of tuples (:class:`tuple`) corresponding to the offices in this
floor. Each tuple has 3 items: the office name (:class:`str`), the
number of seats in this office (:class:`int`) and the number of
occupied seats (:class:`int`). Besides a name, each floor has a number
which is the index (position) of the floor in the nested list.

Write function :py:func:`offices` that takes a list as that described
and creates a number of files equal to the number of floors in the
company building. The name of these files begins with ``'floor'``,
then it goes the floor name and the floor number and ends with the
extension ``'.txt'``. These files have a line for each office in the
corresponding floor that has free seats, with the name (:class:`str`)
and free seats (:class:`int`) of this office, separated by a colon
(``':'``).

Save this function in file ``offices.py``.

Example:

The following statements:

.. literalinclude:: test-offices.txt
   :language: python
   :lines: 3-5

define a company building with two floors with names ``'A'`` and
``'B'`` and numbers ``0`` and ``1``, respectively, and will create two
files with names ``'floorA0.txt'`` and ``'floorB1.txt'``.

The contents of file ``'floorA0.txt'`` will be:

.. literalinclude:: solution/floorA0.txt
   :language: text

and the contents of file ``'floorB1.txt'`` will be:

.. literalinclude:: solution/floorB1.txt
   :language: text
	    
.. note::

   Tests for automatic debugging are provided in file :download:`test-offices.txt`.