a-a a-c aaa aac aak aao aav ac- aca acc ack aco acv aka akc akk ako akv aoa aoc aok aoo aov av- ava avc avk avo c-- caa cac cak cao cav cca ccc cck cco ccv cka ckc cko co- coa coc cok coo cov cva cvc cvk cvo cvv ka- kaa kac kak kao kav kca kcc kck kkc kkk kkv koa koc kok koo kva kvk kvo kvv oaa oac oak oao oav oc- oca occ ock oco ocv oka okc okk oko oo- ooa ooc ook ooo oov ov- ova ovc ovo ovv v-a vaa vac vak vao vav vca vcc vco vka voa voc vok voo vov vva vvc vvo vvv