Journal Division into Balanced sub pages

This workflow takes a spreadsheet containing journal numbers and amounts for a series of balancing journals (i.e. amounts within each journal sum to zero), and then finds subsets of balancing items such that they fit to a "journal page" of a given size (e.g. 900 entries per page).
The result is a division of the data into "sub journals" such that the balance of each sub journal is also zero.

There is no relationship between any lines, and so a subset may consist of any available lines.

A line may only appear once in the result.

Every subjournal page will sum to zero.

Every original line will appear in a subjournal page.