Number "ups"

I remember - from the distant past - a free little piece of software that could tell you "how many up"
of each would best fit on a sheet, if you gave it the info.

I constantly need to do digital impositions where the combination press sheets may have
50 of 5 cards
350 of the next card
750 of another card
125 of 4 cards
500 of 10 cards
etc - etc - etc.

I am not looking for imposition software - mine is great
I just need to figure the best value of "ups."

Unless:
someone knows of software that can read the meta data (xmf or whatever it is)
that is tagged to a file from an online storefront (XMPie)
and can use all of the internal data, along with the PDFs, to create the imposition.

MSD