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 ":".
Since
the
1980s
,
a
number
of
European
and
international
institutions
have
made
Maastricht
their
base
.
Since:O
the:O
1980s:O
,:O
a:O
number:O
of:O
European:location-GPE
and:O
international:O
institutions:O
have:O
made:O
Maastricht:location-GPE
their:O
base:O
.:O