def
f5
(
lst
,
_lstm
=
sys
.
maxint
)
:
# martineau min-tracker version
d
=
{
}
for
item
in
lst:
v
=
item
[
1
]
if
v:
d.
setdefault
(
v
,
{
}
)
[
item
]
=
0
if
v
<
_lstm:
_lstm
=
v
return
d
[
_lstm
]
.
keys
(
)