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 ":".
The
state
of
Kievan
Rus
'
fell
during
the
13th
century
in
the
Mongol
invasion
.
The:O
state:O
of:O
Kievan:location-GPE
Rus:location-GPE
':O
fell:O
during:O
the:O
13th:O
century:O
in:O
the:O
Mongol:location-GPE
invasion:O
.:O