mysql - Subtract 1 From Query Result -

select count(p.pid) department d, professor p d.did = ? , p.did = d.did; 

i subtract '1' result count(p.pid) . instance if value of p.pid 10, output 9... ??

select count(p.pid) - 1 pid_count  department d, professor p  d.did = ? , p.did = d.did;