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: July
17
Schlumberger
NV
,
the
world
's
No.1
oilfield
services
provider
,
said
it
will
look
at
operating
in
Iran
once
the
sanctions
are
lifted
.
Answer: 
July:O
17:O
Schlumberger:B-ORG
NV:I-ORG
,:O
the:O
world:O
's:O
No.1:O
oilfield:O
services:O
provider:O
,:O
said:O
it:O
will:O
look:O
at:O
operating:O
in:O
Iran:B-LOC
once:O
the:O
sanctions:O
are:O
lifted:O
.:O