With no explanation, label each line with "O", "person-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
four
internal
staircases
at
the
corners
of
the
rotunda
leading
to
four
exits
were
Swartwout
's
contribution
.
The:O
four:O
internal:O
staircases:O
at:O
the:O
corners:O
of:O
the:O
rotunda:O
leading:O
to:O
four:O
exits:O
were:O
Swartwout:person-other
's:O
contribution:O
.:O