With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
He
remained
with
the
youth
team
until
the
summer
of
2010
,
when
he
signed
a
short-term
three-month
contract
.
He:O
remained:O
with:O
the:O
youth:O
team:O
until:O
the:O
summer:O
of:O
2010:O
,:O
when:O
he:O
signed:O
a:O
short-term:O
three-month:O
contract:O
.:O