Matching Pairs

Hi,

Any help please I have a large list of data with duplicate pairs of identical data across 3 columns and would like some way to mark each pair with a unique reference index number as seen in the example enclosed.

In the example rows 2 & 3 have identical data so would like to mark as pair #1
In rows 4 & 5 again matching so pair #2
In rows 6 & 8 again matching so pair #3
etc

Thanks in anticipation
G