6  (This is four stack cells from Plate 6 of Mead and Conway.)
1 1 vd pl pl
1 2 pl tr d
1 3 pl c gd

1 5 il sr a
2 1 ol tr b
2 2 ol a gd
2 3 vd jm jm

1 1 vd ol ol
2 3 a tr om
3 1 b sl im
3 2 om b gd
3 3 vd om om
1 6 jl sr c
2 6 c tr pm
3 4 d sl jm
3 5 pm d gd
3 6 vd pm pm
4 1 vd im im
4 2 im e gd
4 3 om sr e*
5 1 im tr f
5 3 e tr or
6 1 f sl ir
6 2 or f gd
6 3 vd or or
4 5 jm g gd
4 6 pm sr g
5 4 jm tr h
5 6 g tr pr
6 4 h sl jr
6 5 pr h gd
6 6 vd pr pr
-100