With no explanation, label each line with "O", "other-currency", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Throughout
its
existence
,
the
obol
was
equal
to
a
British
half
penny
.
Throughout:O
its:O
existence:O
,:O
the:O
obol:other-currency
was:O
equal:O
to:O
a:O
British:other-currency
half:other-currency
penny:other-currency
.:O