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 ":".
He
joined
the
Soviet
partisans
behind
the
German
front
lines
in
September
1941
.
He:O
joined:O
the:O
Soviet:location-GPE
partisans:O
behind:O
the:O
German:location-GPE
front:O
lines:O
in:O
September:O
1941:O
.:O