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: It
gets
pretty
depressing
The
10
youngest
people
on
the
Forbes
400
list
and
how
they
got
there
Answer: 
It:O
gets:O
pretty:O
depressing:O
The:O
10:O
youngest:O
people:O
on:O
the:O
Forbes:O
400:O
list:O
and:O
how:O
they:O
got:O
there:O