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 ":".
Flooding
in
London
has
been
a
problem
since
the
city
was
first
established
in
Roman
times
.
Flooding:O
in:O
London:location-GPE
has:O
been:O
a:O
problem:O
since:O
the:O
city:O
was:O
first:O
established:O
in:O
Roman:location-GPE
times:O
.:O