$ sudo apt-get remove pen 

Uninstall pen including dependent package

If you would like to remove pen and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove pen 

Use Purging pen

If you use with purge options to pen package all the configuration and dependent packages will be removed.

$ sudo apt-get purge pen 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove pen 

See Also,