c-- ccc cce ccs ccx ccz ce- cec cee ces cex cez csc cse css csx csz cxc cxs cxx cz- czc cze ec- ecc ece ecs ecx eec eee ees eex es- esc ese ess esx ex- exc exe exs exx eze ezs ezz scc sce scs scx se- sec see ses sex sez ss- ssc sse sss ssx ssz sxc sxs sze xcx xee xes xex xsc xss xxx zce zcs zec zee zes zez zse zsz zxx zzs zzx zzz