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 ":".
Sometimes
the
concerts
were
regarded
as
unwanted
noise
(
``
''
)
,
causing
conflicts
with
the
police
.
Sometimes:O
the:O
concerts:O
were:O
regarded:O
as:O
unwanted:O
noise:O
(:O
``:O
'':O
):O
,:O
causing:O
conflicts:O
with:O
the:O
police:O
.:O