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 ":".
After
arriving
in
Athens
on
September
23
,
he
quickly
established
contact
with
officers
and
politicians
.
After:O
arriving:O
in:O
Athens:O
on:O
September:O
23:O
,:O
he:O
quickly:O
established:O
contact:O
with:O
officers:O
and:O
politicians:O
.:O