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 ":".
Before
retreating
,
he
was
able
to
ignite
the
magazine
and
destroy
other
provisions
.
Before:O
retreating:O
,:O
he:O
was:O
able:O
to:O
ignite:O
the:O
magazine:O
and:O
destroy:O
other:O
provisions:O
.:O