With no explanation, label each line with "O", "product-software", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Skype
allows
video
conference
calls
.
Skype:product-software
allows:O
video:O
conference:O
calls:O
.:O