a-a a-b aaa aab aah aak aao aav ab- aba abb abh abk abo abv aha ahb ahh ahk aho ahv aka akb akh akk ako akv aoa aob aoh aok aoo aov av- ava avb avh avk avo baa bab bah bak bao bav bba bbb bbh bbk bbo bha bhb bhh bhk bho bhv bka bkb bkk bko bkv boa bob boh bok boo bov bva bvb bvh bvk bvo bvv haa hab hah hak hao hav hba hbb hbh hbk hbo hbv hha hhb hhh hhk hho hhv hka hkb hkh hkk hko hoa hob hoh hok hoo hov hv- hva hvb hvk hvo hvv ka- kaa kab kah kak kao kav kba kbb kbh kbk kbo kha khh khk kho khv kkb kkh kkk kkv koa kob koh kok koo kva kvb kvh kvk kvo kvv oaa oab oah oak oao oav ob- oba obb obh obk obo obv oha ohh oho oka okb okk oko oo- ooa oob ooh ook ooo oov ov- ova ovb ovh ovo ovv v-a vaa vab vah vak vao vav vba vbh vbk vbo vbv vh- vha vhb vho vka vkb voa vob voh vok voo vov vva vvb vvo vvv