With no explanation, label each line with "person-politician", "location-GPE", "O", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting" or "art-writtenart" preceded by ":".
It
began
as
an
organized
insurrection
of
Yaik
Cossacks
headed
by
Yemelyan
Pugachev
,
a
disaffected
ex-lieutenant
of
the
Imperial
Russian
Army
,
against
a
background
of
profound
peasant
unrest
and
war
with
the
Ottoman
Empire
.
It:O
began:O
as:O
an:O
organized:O
insurrection:O
of:O
Yaik:event-attack/battle/war/militaryconflict
Cossacks:event-attack/battle/war/militaryconflict
headed:O
by:O
Yemelyan:person-politician
Pugachev:person-politician
,:O
a:O
disaffected:O
ex-lieutenant:O
of:O
the:O
Imperial:O
Russian:location-GPE
Army:O
,:O
against:O
a:O
background:O
of:O
profound:O
peasant:O
unrest:O
and:O
war:O
with:O
the:O
Ottoman:location-GPE
Empire:location-GPE
.:O