countif counta with multiple lookup criteria

have 2 sheets, one summary, and one detail.

The detail is as follows:


Dept units
331 12
331 24
331
331 12
332
332 36
332 24
333

The summary is as follows:


Dept # of styles
331 3
332 2
333 0

I want the formula on the summary sheet to count the number of non blank entries for each dept.

Which formula is it?

Check your other post for answers.

Regards

Jean-Guy