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 ":".
Until
roughly
1490
,
the
Swiss
had
a
virtual
monopoly
on
pike-armed
mercenary
service
.
Until:O
roughly:O
1490:O
,:O
the:O
Swiss:O
had:O
a:O
virtual:O
monopoly:O
on:O
pike-armed:O
mercenary:O
service:O
.:O