a-a a-b aaa aab aae aak aao aas aav ab- aba abb abe abk abo abs abv aea aeb aee aek aeo aes aev aka akb ake akk ako aks akv aoa aob aoe aok aoo aos aov as- asa asb ase ask aso ass asv av- ava avb ave avk avo avs baa bab bae bak bao bas bav bba bbb bbe bbk bbo bbs be- bea beb bee bek beo bes bev bka bkb bke bkk bko bks bkv boa bob boe bok boo bos bov bsa bsb bse bsk bso bss bsv bva bvb bve bvk bvo bvs bvv eaa eab eae eak eao eas eav eba ebb ebe ebk ebo ebs ebv eea eeb eee eek eeo ees eev eka ekb eke eko eks ekv eo- eoa eob eoe eok eoo eos es- esa esb ese esk eso ess esv eva evb eve evo evs evv ka- kaa kab kae kak kao kas kav kba kbb kbe kbk kbo kbs ke- kea keb kee kek keo kes kev kkb kke kkk kks kkv koa kob koe kok koo kos ksa ksb kse ksk kso kss ksv kva kvb kvk kvo kvs kvv oaa oab oae oak oao oas oav ob- oba obb obe obk obo obs obv oea oeb oee oeo oes oka okb oke okk oko oks oo- ooa oob ook ooo oos oov os- osa osb ose osk oso oss osv ov- ova ovb ove ovo ovs ovv saa sab sae sak sao sas sav sba sbb sbe sbk sbo sbs sbv se- sea seb see sek seo ses sev sk- ska skb ske skk sko sks soa sob soe sok soo sos sov ss- ssa ssb sse ssk sso sss ssv sva svb sve svk svo svs svv v-a v-e vaa vab vae vak vao vas vav vba vbk vbo vbs vbv vea veb vee vek veo ves vka vkb voa vob voe vok voo vos vov vsa vsb vse vsk vso vss vsv vva vvb vvo vvs vvv