What are the country code and first name of the players who won in both tourney WTA Championships and Australian Open?
return players ;return tourneys #1 won ;return #1 where #2 is  WTA Championships ;return #1 where #2 is  Australian Open ;return #1 of  both #3 and  #4 ;return country codes of  #5 ;return first names of  #5 ;return #6 ,  #7
['select', 'project', 'comparative', 'comparative', 'intersection', 'project', 'project', 'union']