a-a a-b aaa aab aak aan aar aav ab- aba abb abk abn abr abv aka akb akk akn akr akv an- ana anb ank ann anr anv ar- ara arb ark arn arr arv av- ava avb avk avn avr baa bab bak ban bar bav bba bbb bbk bbn bbr bka bkb bkk bkn bkr bkv bna bnb bnk bnn bnr bnv bra brb brk brn brr brv bva bvb bvk bvn bvr bvv ka- kaa kab kak kan kar kav kba kbb kbk kbn kbr kkb kkk kkn kkr kkv kn- kna knk knn knr kra krk krn krr krv kva kvb kvk kvn kvr kvv naa nab nak nan nar nav nba nbb nbk nbn nbr nbv nka nkk nkn nkr nna nnb nnk nnn nnv nra nrb nrk nrn nrr nrv nva nvb nvk nvn nvv ra- raa rab rak ran rar rav rba rbb rbk rbn rbr rkb rkk rkv rna rnb rnn rnr rnv rra rrb rrk rrn rrr rva rvb rvn rvr rvv v-a vaa vab vak van var vav vba vbk vbr vbv vka vkb vn- vna vnr vnv vra vrb vrk vrn vrr vva vvb vvr vvv