With no explanation, label each line with "O", "organization-politicalparty", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
During
the
1970s
,
the
PKK
was
involved
in
urban
warfare
.
During:O
the:O
1970s:O
,:O
the:O
PKK:organization-politicalparty
was:O
involved:O
in:O
urban:O
warfare:O
.:O