$ sudo apt-get remove longrun 

Uninstall longrun including dependent package

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

$ sudo apt-get remove --auto-remove longrun 

Use Purging longrun

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

$ sudo apt-get purge longrun 

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 longrun 

See Also,