map  { $_->[0] }
   sort { $a->[1] cmp $b->[1] }
   map  { my ($m, $d, $y) = m{(\d\d)/(\d\d)/(\d\d)};
          $y += y >= $cutoff ? 1900 : 2000;
          [ $_, sprintf('%04d/%02d/%02d', $y, $m, $d) ]
        }