With no explanation, label each line with "location-GPE", "O", "product-ship", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
From
July
1967
to
December
1968
``
Brereton
``
was
converted
to
a
minehunter
at
Portsmouth
.
From:O
July:O
1967:O
to:O
December:O
1968:O
``:O
Brereton:product-ship
``:O
was:O
converted:O
to:O
a:O
minehunter:O
at:O
Portsmouth:location-GPE
.:O