With no explanation, label each line with "location-GPE", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
About
30
protesters
gathered
in
stormy
weather
in
San
Mateo
.
About:O
30:O
protesters:O
gathered:O
in:O
stormy:O
weather:O
in:O
San:location-GPE
Mateo:location-GPE
.:O