I need the formula to count the number of unique resources.

Column A

Column A

**Column L**

Category

Category

**Resource name**

BA-3 AAA

BA-3 ABC

BA-3 AAA

BA-3 BBB

BA-3 ABC

BA-3 BCD

BA-3 BBB

BA-3 ABC

What would be the formula to count the unique Resources for which the Category is BA-3

Regards,

Chuck