Compare Revit room/area with excel

Hi Guys!

I need to compare rooms and its associated area with an external list. I have filtered and sorted both lists equal, and need to compare them. I use List.Contain + List.FilterByBooleanMask. Everything looks fine, it filters out all rooms with different areas - NOTE this is ONLY if rooms appear in BOTH lists. Once a room is only represented in one of the lists (Revit in this case) the indexing do not match anymore.

Am I doing something totally wrong, or is there another way to do this - maybe like the LoopWhile node fx?

I solved my problem, if any should be interested! My problem was my data modelling. What I did was to filter out all new/changed rooms that did not match the excel list. THEN it was possible to match room and areas by index!

A lot of sorting and grouping, then filtering and then match the items