With no explanation, label each line with "location-GPE", "O", "other-law", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting" or "art-writtenart" preceded by ":".
After
the
end
of
World
War
II
,
Poland
became
a
communist
country
which
joined
the
Warsaw
Pact
.
After:O
the:O
end:O
of:O
World:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
II:event-attack/battle/war/militaryconflict
,:O
Poland:location-GPE
became:O
a:O
communist:O
country:O
which:O
joined:O
the:O
Warsaw:other-law
Pact:other-law
.:O