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 ":".
Primary
mission
was
fighter
escort
;
air
defense
using
night
fighter
units
;
harbor
protection
;
homing
of
lost
aircraft
and
air-sea
rescue
.
Primary:O
mission:O
was:O
fighter:O
escort:O
;:O
air:O
defense:O
using:O
night:O
fighter:O
units:O
;:O
harbor:O
protection:O
;:O
homing:O
of:O
lost:O
aircraft:O
and:O
air-sea:O
rescue:O
.:O