COUNTIFS - Counting in order in one column, Counting only specific cells In another

I probably described this terribly in the topic, but here's the issue:


I have a sheet full of unique entries (each row is a new entry) -- column A has the identification for each participant. Participants can have multiple entries.

I'm able to easily count (in order) each unique record depending on participant ID, using =COUNTIF($A$1:A2,A2).


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PROBLEM: Not every entry is considered "VALID." Whether or not the entry is considered valid is contained in a different cell in the same row. That column only has "VALID" or "INVALID."

I want to be able to count, in order (i.e. 1, 2, 3) only the VALID entries. The INVALID entries would ideally be blank or have something distinguishing them.