Which staff members who reported problems from the product "rem" but not "aut"? Give me their first and last names.
select t3.staff_first_name, t3.staff_last_name from problems as t1 join product as t2 join staff as t3 on t1.product_id = t2.product_id and t1.reported_by_staff_id = t3.staff_id where t2.product_name = "rem" except select t3.staff_first_name, t3.staff_last_name from problems as t1 join product as t2 join staff as t3 on t1.product_id = t2.product_id and t1.reported_by_staff_id = t3.staff_id where t2.product_name = "aut"