#ignore + - \ / ^ &
#axiom
S(0)
#rules
S(a) : a<8 -> S(a+1)
S(a) : a>=8 -> M(0)\(90)[+G(2,2)][-G(2,2)]S(0)
M(a) : a<17 -> M(a+1)
M(a) : a>=17 -> L(0)M(0)
G(a,b) : b<7 -> G(a,b+1)
G(a,b) : b>=7 -> G(1,1)[+G(0,0)][-O(1,1)[+B][-B][\B]B]
W -> W
B -> B