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 ":".
The
2008
presidential
election
was
the
first
since
1952
in
which
neither
an
incumbent
president
nor
an
incumbent
vice
president
was
a
candidate
.
The:O
2008:O
presidential:O
election:O
was:O
the:O
first:O
since:O
1952:O
in:O
which:O
neither:O
an:O
incumbent:O
president:O
nor:O
an:O
incumbent:O
vice:O
president:O
was:O
a:O
candidate:O
.:O