select count(s.name) from sheldule h, subjects s, days_week d, corps c, audiences a
where s.id = h.subject_id
and a.id = h.audience_id
and a.corp_id = c.id
and d.id = h.day_id
and c.name = 'Центральний'
and d.name = 'Середа'


select distinct d.name from sheldule h, subjects s, days_week d,  audiences a
    where s.id = h.subject_id
        and a.id = h.audience_id
        and d.id = h.day_id
        and d.name not in
            (select D.name from sheldule H, days_week D, audiences A
                where A.id = H.audience_id
                    and D.id = H.day_id
                    and A.name = '410'
             );