In the list of tokens, identify 'Person', 'Location', and 'Organisation' and label each accordingly. If the entity spans multiple tokens, use the prefix B-PER, B-LOC, or B-ORG for the first token, and I-PER, I-LOC, or I-ORG for the subsequent tokens of that entity. The beginning of each separate entity should always be labeled with a B-PER, B-LOC, or B-ORG prefix. If the token does not fit into any of the three named categories, or is not a named entity, label it as 'O'. Each line should contain one token and its corresponding label, separated by a colon. Do not combine tokens on your own. The format for each line should be: 'token:label'.

Text: However
,
the
challenge
has
been
with
the
small
and
medium
scale
enterprises
(
SMEs
)
,
many
of
whom
do
not
adhere
to
standards
and
are
mostly
not
registered
which
makes
it
difficult
to
track
them
.
Answer: 
However:O
,:O
the:O
challenge:O
has:O
been:O
with:O
the:O
small:O
and:O
medium:O
scale:O
enterprises:O
(:O
SMEs:O
):O
,:O
many:O
of:O
whom:O
do:O
not:O
adhere:O
to:O
standards:O
and:O
are:O
mostly:O
not:O
registered:O
which:O
makes:O
it:O
difficult:O
to:O
track:O
them:O
.:O