Is there a way to get the count of different facets in solr?

This is an example facet:

* Camera: 20
* Computer: 80
* Monitor: 40
* Laptop: 120
* Tablet: 30

What I need to get here is "5" as in 5 different electronic items. Of course I can count the facet but some of them have many items inside and fetching and counting them really slow it down.