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 ":".
In
the
late
1990s
,
the
S-3B
's
mission
focus
shifted
to
surface
warfare
and
aerial
refueling
.
In:O
the:O
late:O
1990s:O
,:O
the:O
S-3B:O
's:O
mission:O
focus:O
shifted:O
to:O
surface:O
warfare:O
and:O
aerial:O
refueling:O
.:O