See if you really want to know then this will let you know
https://www.lynda.com/Flickr-tutorials/Sharing-Photos-Flickr/435438-2.html
It will cost you about £14 per month but then again you can always brush up on other things like Lightroom, Photoshop etc.

I do a lot of Flickr work and I learned a thing or two, including how versatile the Camera Roll can be with bulk editing.