Return the id of the customer who has the most cards, as well as the number of cards.
return customers ;return cards  of  #1 ;return number of  #2 for each  #1 ;return #1 where  #3 is highest ;return id of  #4 ;return number of  cards  of  #4 ;return #5 ,  #6
['select', 'project', 'group', 'superlative', 'project', 'project', 'union']