Merge pull request #3 from julian-upc/master

Updating
new file
Create README
sheet3
Merge pull request #118 from aitor-perez/master

added code for sheet3
Merge pull request #117 from arnauplanas/master

sheet3: code, readme and diary
Merge pull request #119 from Gwenaelaurent/master

sheet3
errors corrected
Merge pull request #120 from Gwenaelaurent/master

errors corrected
Added sheet3 at last. Sorry for the lateness.
Merge pull request #121 from lafaillette/master

Added sheet3 at last. Sorry for the lateness.
added 12/16 report