How To Find Orphaned Value From Parent / Child Hierarchy Table

how to find the orphaned value from the below parent/child hierarchy Table.

create table dbo.Hier(parent varchar(100), child varchar(100))

insert into Hier
select 'subramanium','Manickam' union all
select 'subramanium','Munuswamy' union all
select 'Munuswamy','senthil' union all
select 'Munuswamy','sasi' union all
select 'Munuswamy','uma' union all
select 'manickam','vijay' union all
select 'manickam','bhavani' union all
select 'manickam','dhanam' union all
select 'uma','varsha'

Delete from Hier where child='uma'

I tried:

select parent from Hier
where parent not in(select Child from Hier)
and parent <> 'subramanium'
Getting resultset as:
parent
======
uma

I need to know whether my select statement is correct or not,if its correct,how to write the same in CTE?