Need to get the UOM with the greatest number in the Sales and Purchase Invoice reports

Fetch the greatest unit from the Item 1’s UNITS OF MEASURE table.

For example:

====================================================================
Item    |  Pack Size  |  Unit  |  Qty  |  Rate
Item 1  | 2 x 60 Pcs  |  Box   |   2   |   999
====================================================================

The bold text if to be fetched from the Item’s UNIT OF MEASURE section which has the highest value (signalling the biggest size of a pack unit).