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: "
As
Blue
Cross
Blue
Cross
Blue
Shield
has
said
about
it
's
planned
merger
with
Cigna
,
now
they
will
have
leverage
to
negotiate
with
physicians
.
Answer: 
":O
As:O
Blue:B-ORG
Cross:I-ORG
Blue:I-ORG
Cross:I-ORG
Blue:I-ORG
Shield:I-ORG
has:O
said:O
about:O
it:O
's:O
planned:O
merger:O
with:O
Cigna:B-ORG
,:O
now:O
they:O
will:O
have:O
leverage:O
to:O
negotiate:O
with:O
physicians:O
.:O