Return the id of the staff whose Staff Department Assignment was earlier than that of any Clerical Staff.
return staffs ;return Clerical Staff ;return Staff Department Assignment of #1 ;return Staff Department Assignment of #2 ;return #1 where #3 is  earlier than  any  #4 ;return the  ids of #5
['select', 'select', 'project', 'project', 'comparative', 'project']