With no explanation, label each line with "location-GPE", "O", "event-disaster", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
During
his
tenure
as
mayor
,
the
Cocoanut
Grove
fire
occurred
in
Boston
.
During:O
his:O
tenure:O
as:O
mayor:O
,:O
the:O
Cocoanut:event-disaster
Grove:event-disaster
fire:event-disaster
occurred:O
in:O
Boston:location-GPE
.:O