It's actually 28 disks that have been copypasted (I recounted) three times, so theoretically 84 disks. But practically you can't say that because you don't see the top deck properly so you can only presume its the same as the pasted one (duh).
But what if it's not?
And btw, you're not counting the complete disk, just the five installments put into one single folder right-click properties. What if the disk has a different size, huh?
If forum options would've been more fun, here'd probably reside some wicked banner image.