a-a a-b a-c a-t aaa aab aac aan aao aar aas aat aau ab- aba abb abc abn abo abr abs abt abu ac- aca acb acc acn aco acr acs act acu an- ana anb anc ann ano anr ans ant anu aoa aob aoc aon aoo aor aos aot aou ar- ara arb arc arn aro arr ars art aru as- asa asb asc asn aso asr ass ast asu at- ata atb atc atn ato atr ats att atu au- aua aub auc aun auo aur aus aut b-u baa bab bac ban bao bar bas bat bau bba bbb bbc bbn bbo bbr bbs bbt bbu bca bcb bcc bcn bco bcr bcs bct bcu bna bnb bnc bnn bno bnr bns bnt bnu boa bob boc bon boo bor bos bot bou bra brb brn bro brr brs brt bru bsa bsb bsc bsn bso bsr bss bst bsu bta btb btc btn bto btr bts btt btu bua bub buc bun buo bur bus but buu c-- caa cab cac can cao car cas cat cau cba cbb cbc cbn cbo cbr cbs cbt cbu cca ccb ccc ccn cco ccr ccs cct ccu cn- cna cnb cnc cnn cno cnr cns cnt cnu co- coa cob coc con coo cor cos cot cou cra crb crc crn cro crr crs crt cru csa csb csc csn cso csr css cst csu cta ctb ctc ctn cto ctr cts ctt ctu cua cub cuc cun cuo cur cus cut cuu naa nab nac nan nao nar nas nat nau nba nbb nbc nbn nbo nbr nbs nbt nbu nca ncb ncc ncn nco ncr ncs nct ncu nna nnb nnc nnn nno nns nnt nnu no- noa nob noc non noo nor nos not nou nra nrb nrc nrn nro nrr nrs nrt nru nsa nsb nsc nsn nso nsr nss nst nsu nta ntb ntc ntn nto ntr nts ntt ntu nua nub nuc nun nuo nur nus nut nuu oaa oab oac oan oao oar oas oat oau ob- oba obb obc obn obo obr obs obt obu oc- oca ocb occ ocn oco ocr ocs oct ocu on- ona onb onc onn ono onr ons ont onu oo- ooa oob ooc oon ooo oor oos oot or- ora orb orc orn oro orr ors ort oru os- osa osb osc osn oso osr oss ost osu ot- ota otb otc otn oto otr ots ott otu ou- oua ouc oun ouo our ous out ra- raa rab rac ran rao rar ras rat rau rba rbb rbc rbn rbo rbr rbs rbt rbu rca rcb rcc rcn rco rcr rcs rct rcu rna rnb rnc rnn rno rnr rns rnt rnu roa rob roc ron roo ror ros rot rou rra rrb rrc rrn rrr rrs rrt rru rsa rsb rsc rsn rso rsr rss rst rsu rta rtb rtc rtn rto rtr rts rtt rtu rua rub ruc run ruo rur rus rut ruu saa sab sac san sao sar sas sat sau sba sbb sbc sbn sbo sbr sbs sbt sbu sca scb scc scn sco scr scs sct scu sna snb snc snn sno snr sns snt snu soa sob soc son soo sor sos sot sou sr- sra srb src srn sro srr srs srt ss- ssa ssb ssc ssn sso ssr sss sst ssu sta stb stc stn sto str sts stt stu sua sub suc sun suo sur sus sut suu taa tab tac tan tao tar tas tat tau tba tbb tbc tbn tbo tbr tbs tbt tbu tca tcb tcc tcn tco tcr tcs tct tcu tna tnb tnc tnn tno tnr tns tnt to- toa tob toc ton too tor tos tot tou tra trb trc trn tro trr trs trt tru tsa tsb tsc tsn tso tsr tss tst tsu tta ttb ttc ttn tto ttr tts ttt ttu tua tub tuc tun tuo tur tus tut tuu ua- uaa uab uac uan uao uar uas uat uau uba ubb ubc ubn ubo ubr ubs ubt ubu uca ucb ucc ucn uco ucr ucs uct ucu un- una unb unc unn uno unr uns unt unu uoa uob uoc uon uoo uor uos uot ur- ura urb urc urn uro urr urs urt uru usa usb usc usn uso usr uss ust usu uta utb utc utn uto utr uts utt utu uua uuc uun uur uus uut uuu