Wells Homepage background image - Cyclying through different images

Site URL: https://www.davidstinsonphoto.com/

Currently, I have one photo that's full bleed for the background image on the home page (I have it set to only display the background image on the homepage). I want it to cycle through maybe 8-10 photos, BUT I do NOT want a slideshow on the home page. I want a different photo to load up randomly each time the homepage is visited (or refreshed). Anyone know the CSS to make this happen? So much appreciated! I'm using the Wells template.