auto count-if with subtotal's autofiltered layout

Hello everyone!

I have a sheet that has two columns: one represents cities and the
other represents devices+code device. Firstly I don't know by prior
how many rows they are; so first, I order cities column, then I put
subtotals grouped by city that counts how many cities they are and I
choose to show subtotals every time city changes then I apply
AutoFilter ON. In this way I can see like a sheet grouped with many
subtotals that tells me how many cities they are.
But really I want to have subtotals that tells me how many printers
there are by each city and how many servers there are always by each
city using something like countif() but still showing the layout in
the same sheet with autofilter on so when I choose a certain city, it
hides other cities and subtotals and keeps showing me the subtotals
for that city.
And I wouldn't like to have pivots table...

How I can do that?

Thanks you to all in advance for this little help.

Ciao,
Luigi