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 ":".
224
Squadron
RAF
attempting
to
make
contact
with
the
convoy
.
224:O
Squadron:O
RAF:O
attempting:O
to:O
make:O
contact:O
with:O
the:O
convoy:O
.:O