(-1/8)*1/9/(1/12-2/3+3/4-5/8)
=-1/[72*(1/12-2/3+3/4-5/8)]
=-1/(72*1/12-72*2/3+72*3/4-72*5/8)
=-1/(6-48+54-45)
=-1/(-33)
=1/33