It is unlawful for any person to congregate or cause to be congregated a crowd of three or more persons upon any public street, alley, sidewalk, parking lot, school or school grounds, building, or any other public place within the city so as to obstruct the same or as to hinder or annoy passersby or occupants of adjacent premises, or as to interfere with the activities normally carried on on the premises.
('75 Code, § 53.25) Penalty, see § 10.99