我開估 我係三號!!!
I guess I'm number three!!!

Cantonese Sentence Breakdown

我 ngo5
I
me
my
us
we
our
self
開估 hooi1 gu3
estimate
係 hai6
(Cantonese) to be
to connect
to relate to
to tie up
to bind
to be (literary)
to involve
relation
relationship
consequence
yes
indeed
right
三號 saam1 hou6
number three