Which document has the most draft copies? List its document id and number of draft copies.
return documents ;return draft  copies  of #1 ;return number of  #2 for each #1 ;return the  highest of #3 ;return #1 where #3 is equal to #4 ;return document  id of #5 ;return #6 ,  #4
['select', 'project', 'group', 'aggregate', 'comparative', 'project', 'union']