With no explanation, label each line with "O", "organization-religion", "person-politician", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
He
started
negotiations
about
the
return
of
the
Bulgarian
Church
to
Orthodoxy
after
the
barons
of
the
Latin
Empire
had
elected
J
ohn
of
Brienne
regent
for
Baldwin
II
in
1229
.
He:O
started:O
negotiations:O
about:O
the:O
return:O
of:O
the:O
Bulgarian:organization-religion
Church:organization-religion
to:O
Orthodoxy:organization-religion
after:O
the:O
barons:O
of:O
the:O
Latin:O
Empire:O
had:O
elected:O
J:O
ohn:person-politician
of:person-politician
Brienne:person-politician
regent:O
for:O
Baldwin:person-politician
II:person-politician
in:O
1229:O
.:O