a-a a-b a-c a-t aaa aab aac aam aao aar aat ab- aba abb abc abm abo abr abt ac- aca acb acc acm aco acr act ama amb amc amm amo amr amt aoa aob aoc aom aoo aor aot ar- ara arb arc arm aro arr art at- ata atb atc atm ato atr att baa bab bac bam bao bar bat bba bbb bbc bbm bbo bbr bbt bca bcb bcc bcm bco bcr bct bma bmb bmc bmm bmo bmr bmt boa bob boc bom boo bor bot bra brb brm bro brr brt bta btb btc btm bto btr btt c-- caa cab cac cam cao car cat cba cbb cbc cbm cbo cbr cbt cca ccb ccc ccm cco ccr cct cma cmb cmc cmm cmo cmr cmt co- coa cob coc com coo cor cot cra crb crc crm cro crr crt cta ctb ctc ctm cto ctr ctt m-o m-r maa mab mac mam mao mar mat mba mbb mbc mbm mbo mbr mbt mc- mca mcb mcc mcm mco mcr mct mma mmb mmc mmm mmo mmr mmt moa mob moc mom moo mor mot mra mrb mrc mrm mro mrr mrt mta mtb mtc mtm mto mtr mtt oaa oab oac oam oao oar oat ob- oba obb obc obm obo obr obt oc- oca ocb occ ocm oco ocr oct om- oma omb omc omm omo omr omt oo- ooa oob ooc oom ooo oor oot or- ora orb orc orm oro orr ort ot- ota otb otc otm oto otr ott ra- raa rab rac ram rao rar rat rba rbb rbc rbm rbo rbr rbt rca rcb rcc rcm rco rcr rct rma rmb rmc rmm rmo rmr rmt roa rob roc rom roo ror rot rra rrb rrc rrm rrr rrt rta rtb rtc rtm rto rtr rtt taa tab tac tam tao tar tat tba tbb tbc tbm tbo tbr tbt tca tcb tcc tcm tco tcr tct tma tmb tmc tmm tmo tmr tmt to- toa tob toc tom too tor tot tra trb trc trm tro trr trt tta ttb ttc ttm tto ttr ttt