With no explanation, label each line with "O", "product-weapon", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
shotgun
has
fallen
in
and
out
of
favor
with
military
forces
several
times
in
its
long
history
.
The:O
shotgun:product-weapon
has:O
fallen:O
in:O
and:O
out:O
of:O
favor:O
with:O
military:O
forces:O
several:O
times:O
in:O
its:O
long:O
history:O
.:O