With no explanation, label each line with "location-GPE", "O", "person-politician", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Emperor
John
III
Doukas
Vatatzes
of
Nicaea
concluded
an
alliance
with
Bulgaria
,
which
in
1235
resulted
in
a
joint
campaign
against
the
Latin
Empire
.
Emperor:O
John:person-politician
III:person-politician
Doukas:person-politician
Vatatzes:person-politician
of:O
Nicaea:location-GPE
concluded:O
an:O
alliance:O
with:O
Bulgaria:location-GPE
,:O
which:O
in:O
1235:O
resulted:O
in:O
a:O
joint:O
campaign:O
against:O
the:O
Latin:location-GPE
Empire:location-GPE
.:O