Counting values based on a criteria with duplicates

Good Afternoon,

I am trying to count the number of times a particular store number appears on a spreadsheet for tracking purposes. The only criteria I need met is that I only want stores to be counted if they are of a particular Division. However, there are going to be duplicates, I only want the store to be counted once, even if it shows up multiple times. I have attached a dummy shreadsheet. I have a small table in H3:I6 that I would want the formulas to be used in. Any help on this matter would be appreciated. Our real file is quite large and would take much too long to count the stores manually.