With no explanation, label each line with "location-GPE", "O", "other-chemicalthing", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Medicated
chewing
gum
containing
aspirin
was
first
sold
in
the
United
States
in
1924
.
Medicated:O
chewing:O
gum:O
containing:O
aspirin:other-chemicalthing
was:O
first:O
sold:O
in:O
the:O
United:location-GPE
States:location-GPE
in:O
1924:O
.:O