With no explanation, label each line with "location-GPE", "O", "event-attack/battle/war/militaryconflict", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
The
large-scale
migration
is
corroborated
by
the
data
collected
during
the
Bulgarian
occupation
of
northeastern
Greece
during
World
War
II
.
The:O
large-scale:O
migration:O
is:O
corroborated:O
by:O
the:O
data:O
collected:O
during:O
the:O
Bulgarian:location-GPE
occupation:O
of:O
northeastern:O
Greece:location-GPE
during:O
World:event-attack/battle/war/militaryconflict
War:event-attack/battle/war/militaryconflict
II:event-attack/battle/war/militaryconflict
.:O