With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
Snow
covers
the
ground
until
at
least
April
;
in
the
snow
pits
melts
even
in
summer
.
Snow:O
covers:O
the:O
ground:O
until:O
at:O
least:O
April:O
;:O
in:O
the:O
snow:O
pits:O
melts:O
even:O
in:O
summer:O
.:O