a-a a-b a-c a-t aaa aab aac aao aar aat aav ab- aba abb abc abo abr abt abv ac- aca acb acc aco acr act acv aoa aob aoc aoo aor aot aov ar- ara arb arc aro arr art arv at- ata atb atc ato atr att atv av- ava avb avc avo avr avt baa bab bac bao bar bat bav bba bbb bbc bbo bbr bbt bca bcb bcc bco bcr bct bcv boa bob boc boo bor bot bov bra brb bro brr brt brv bta btb btc bto btr btt btv bva bvb bvc bvo bvr bvt bvv c-- caa cab cac cao car cat cav cba cbb cbc cbo cbr cbt cbv cca ccb ccc cco ccr cct ccv co- coa cob coc coo cor cot cov cra crb crc cro crr crt crv cta ctb ctc cto ctr ctt ctv cva cvb cvc cvo cvr cvt cvv oaa oab oac oao oar oat oav ob- oba obb obc obo obr obt obv oc- oca ocb occ oco ocr oct ocv oo- ooa oob ooc ooo oor oot oov or- ora orb orc oro orr ort orv ot- ota otb otc oto otr ott otv ov- ova ovb ovc ovo ovv ra- raa rab rac rao rar rat rav rba rbb rbc rbo rbr rbt rca rcb rcc rco rcr rct rcv roa rob roc roo ror rot rov rra rrb rrc rrr rrt rta rtb rtc rto rtr rtt rtv rva rvb rvc rvo rvr rvt rvv taa tab tac tao tar tat tav tba tbb tbc tbo tbr tbt tbv tca tcb tcc tco tcr tct tcv to- toa tob toc too tor tot tov tra trb trc tro trr trt trv tta ttb ttc tto ttr ttt ttv tva tvb tvc tvo tvr tvt v-a vaa vab vac vao var vat vav vba vbc vbo vbr vbv vca vcc vco vcr vct voa vob voc voo vor vot vov vra vrb vrc vrr vrt vta vtb vtc vto vtr vtt vtv vva vvb vvc vvo vvr vvt vvv