Find the first name of student who is taking classes from accounting and Computer Info. Systems departments
return students ;return classes #1 are  taking ;return departments of  #2 ;return #1 where #3 is  Computer Info Systems ;return #1 where #3 is  accounting ;return #1 of  both #4 and  #5 ;return first name of  #6
['select', 'project', 'project', 'comparative', 'comparative', 'intersection', 'project']