What are the first name and gender of the students who have allergy to milk but can put up with cats?
return students ;return allergy of  #1 ;return #1 where #2 is  milk ;return #1 where #2 is  not  cats ;return #1 of  both #3 and  #4 ;return first names of  #5 ;return gender of  #5 ;return #6 ,  #7
['select', 'project', 'comparative', 'comparative', 'intersection', 'project', 'project', 'union']