a-a a-c aaa aac aae aak aao aav ac- aca acc ace ack aco acv aea aec aee aek aeo aev aka akc ake akk ako akv aoa aoc aoe aok aoo aov av- ava avc ave avk avo c-- caa cac cae cak cao cav cca ccc cce cck cco ccv ce- cea cec cee cek ceo cev cka ckc cko co- coa coc coe cok coo cov cva cvc cve cvk cvo cvv eaa eac eae eak eao eav ec- eca ecc ece eck eco ecv eea eec eee eek eeo eev eka ekc eke eko ekv eo- eoa eoc eoe eok eoo eva evc eve evo evv ka- kaa kac kae kak kao kav kca kcc kce kck ke- kea kec kee kek keo kev kkc kke kkk kkv koa koc koe kok koo kva kvk kvo kvv oaa oac oae oak oao oav oc- oca occ ock oco ocv oea oec oee oeo oka okc oke okk oko oo- ooa ooc ook ooo oov ov- ova ovc ove ovo ovv v-a v-e vaa vac vae vak vao vav vca vcc vce vco vea vec vee vek veo vka voa voc voe vok voo vov vva vvc vvo vvv