What is the minimum number of pages that can be Saddle-Stitched for a Plus Cover Book?

Saddle-Stitching requires the page count to be in multiples of four because there are 4 book pages printed on each sheet. There need to be at least two sheets (8 pages) for the inside of the book so that the minimum number would be 8 inside pages plus 4 covers pages, for a total of 12.