a-a a-b a-c a-t aaa aab aac aag aao aar aas aat aau ab- aba abb abc abg abo abr abs abt abu ac- aca acb acc acg aco acr acs act acu ag- aga agb agc agg ago agr ags agt agu aoa aob aoc aog aoo aor aos aot aou ar- ara arb arc arg aro arr ars art aru as- asa asb asc asg aso asr ass ast asu at- ata atb atc atg ato atr ats att atu au- aua aub auc aug auo aur aus aut b-u baa bab bac bag bao bar bas bat bau bba bbb bbc bbg bbo bbr bbs bbt bbu bca bcb bcc bcg bco bcr bcs bct bcu bga bgb bgc bgg bgo bgr bgs bgt bgu boa bob boc bog boo bor bos bot bou bra brb brg bro brr brs brt bru bsa bsb bsc bsg bso bsr bss bst bsu bta btb btc btg bto btr bts btt btu bua bub buc bug buo bur bus but buu c-- caa cab cac cag cao car cas cat cau cba cbb cbc cbg cbo cbr cbs cbt cbu cca ccb ccc ccg cco ccr ccs cct ccu cga cgb cgc cgg cgo cgr cgs cgt cgu co- coa cob coc cog coo cor cos cot cou cra crb crc crg cro crr crs crt cru csa csb csc csg cso csr css cst csu cta ctb ctc ctg cto ctr cts ctt ctu cua cub cuc cug cuo cur cus cut cuu gaa gab gac gag gao gar gas gat gau gba gbc gbg gbo gbr gbs gbt gbu gca gcb gcc gcg gco gcr gcs gct gcu gga ggb ggc ggg ggo ggr ggs ggt ggu goa gob goc gog goo gor gos got gou gra grb grc grg gro grr grs grt gru gsa gsb gsc gsg gso gsr gss gst gsu gta gtb gtc gtg gto gtr gts gtt gtu gu- gua gub guc gug guo gur gus gut guu oaa oab oac oag oao oar oas oat oau ob- oba obb obc obg obo obr obs obt obu oc- oca ocb occ ocg oco ocr ocs oct ocu oga ogc ogg ogo ogs ogt oo- ooa oob ooc oog ooo oor oos oot or- ora orb orc org oro orr ors ort oru os- osa osb osc osg oso osr oss ost osu ot- ota otb otc otg oto otr ots ott otu ou- oua ouc ouo our ous out ra- raa rab rac rag rao rar ras rat rau rba rbb rbc rbg rbo rbr rbs rbt rbu rca rcb rcc rcg rco rcr rcs rct rcu rga rgb rgc rgg rgo rgr rgs rgt roa rob roc rog roo ror ros rot rou rra rrb rrc rrg rrr rrs rrt rru rsa rsb rsc rsg rso rsr rss rst rsu rta rtb rtc rtg rto rtr rts rtt rtu rua rub ruc rug ruo rur rus rut ruu saa sab sac sag sao sar sas sat sau sba sbb sbc sbg sbo sbr sbs sbt sbu sca scb scc scg sco scr scs sct scu sga sgb sgc sgg sgo sgr sgs sgt sgu soa sob soc sog soo sor sos sot sou sr- sra srb src srg sro srr srs srt ss- ssa ssb ssc ssg sso ssr sss sst ssu sta stb stc stg sto str sts stt stu sua sub suc sug suo sur sus sut suu taa tab tac tag tao tar tas tat tau tba tbb tbc tbg tbo tbr tbs tbt tbu tca tcb tcc tcg tco tcr tcs tct tcu tga tgb tgc tgg tgo tgr tgs tgt tgu to- toa tob toc tog too tor tos tot tou tra trb trc trg tro trr trs trt tru tsa tsb tsc tsg tso tsr tss tst tsu tta ttb ttc ttg tto ttr tts ttt ttu tua tub tuc tug tuo tur tus tut tuu ua- uaa uab uac uag uao uar uas uat uau uba ubb ubc ubg ubo ubr ubs ubt ubu uca ucb ucc ucg uco ucr ucs uct ucu uga ugb ugc ugg ugo ugr ugs ugt ugu uoa uob uoc uog uoo uor uos uot ur- ura urb urc urg uro urr urs urt uru usa usb usc usg uso usr uss ust usu uta utb utc uto utr uts utt utu uua uuc uug uur uus uut uuu