What is the output of

Declare @t table(id int identity, col1 int, col2 int, col3 int, col4 int, col5 int)
insert into @t values(23,33,44,55,66),(101,11,304,55,6),(7,3,5,9,1),(4,5,3,6,7),(1,2,3,4,5)

select
(
select max(n) from
(
values(col1),(col2),(col3),(col4),(col5)
) as t(n)
)
from @t