Email
=====

We wish to automatically generate the email of a given professor according to its name, department and university:

    - The name is provided as a string with 2 or 3 words separated by '.'
    - The department and the university are provided as a string with at most 3 words separated by ' ' (it can be a single word).
    
The generated email must have the following format:

    - The username: The first two letters of each of the words in its name, in lowercase. For instance if the name is ``'Lluís Vila Grabulosa'`` the username is ``'llvigr'``.
    - The ``@`` symbol.
    - The domain formed with two words separated by ``'.'``: The first three letters of each of the words of the departament and the initials of the university, both in lowercase.
    - The extension ``.edu``.
    
Implement the following two Python functions in the module :mod:`email` (file :file:`email.py`. Starting with the second one is recommended.

The first function is:

    **email(name, dep, uni)**
        | takes ``name, dep, uni``, :class:`str` according to the definition above
        | returns a :class:`str` with the email corresponding to this person according to the description above.

For exemple:

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

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

    **xtr_inis(s, sep, n)**
    
        | takes
        | - ``s`` a :class:`str` formed by 1, 2 or 3 words separated by the characte ``sep``.
        | - ``sep`` a :class:`str`.
        | - ``n`` a positive :class:`int`.
        
        | returns a :class:`str` formed with the n initial characters of the words in ``s``,  in lowercase

For exemple:

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