Counting cells in B based on text in column A

Hello,

I have a 2 column Excel sheet: Column A contains a random assortment of months (January - December). Column B contains various names (see attachment).

I would like a cell in a separate workbook to give me the total cells in column B that have January in column A. However, there may be duplicates, which I do not want (There could be multiple rows that have January in column A & Sarah in column B, but they should only count as 1).

So far I've been able to use COUNTIF to count how many cells are in a column, minus the duplicates: =SUM(1/COUNTIF(Range1,Range1))
I've also been able to use COUNTIFS to get a sum of how many cells contain a specific string of text:=COUNTIFS(Range2,"criteria2")

I think I need to combine these 2 in some way, but I can't quite figure out how to do it.

Can anyone help me out here? I'd really appreciate it!

Thanks =]

Jackie