What are the distinct first names and cities of the students who have allergy either to milk or to cat?
return students ;return allergy of #1 ;return #1 where #2 is  to  milk ;return #1 where #2 is  to  cat ;return #3 or  #4 ;return distinct first names of #5 ;return cities of #5 ;return #6 ,  #7
['select', 'project', 'comparative', 'comparative', 'union', 'project', 'project', 'union']