Which cities do more than one employee under age 30 come from?
return cities ;return employees from  #1 ;return ages of #2 ;return #2 where #3 is  under 30 ;return number of #4 for each #1 ;return #1 where #5 is  more than  one
['select', 'project', 'project', 'comparative', 'group', 'comparative']