select t1.emp_no  ,t2.emp_no as manager
	from(
	select e.emp_no,d.dept_no
	from dept_emp e join dept_manager  d using(dept_no)
	)t1
	left join (
	
	select  dept_no, emp_no from dept_manager
	)t2  on   t1.dept_no = t2.dept_no
	where t1.emp_no != t2.emp_no