With no explanation, label each line with "O", "person-politician", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
Persian
part
of
the
empire
was
threatened
by
the
Parthian
kingdom
,
and
Timarchus
probably
spent
much
of
his
time
reinforcing
the
defences
.
The:O
Persian:O
part:O
of:O
the:O
empire:O
was:O
threatened:O
by:O
the:O
Parthian:O
kingdom:O
,:O
and:O
Timarchus:person-politician
probably:O
spent:O
much:O
of:O
his:O
time:O
reinforcing:O
the:O
defences:O
.:O