a-a a-b a-c a-t aaa aab aac aao aar aas aat aau ab- aba abb abc abo abr abs abt abu ac- aca acb acc aco acr acs act acu aoa aob aoc aoo aor aos aot aou ar- ara arb arc aro arr ars art aru as- asa asb asc aso asr ass ast asu at- ata atb atc ato atr ats att atu au- aua aub auc auo aur aus aut b-u baa bab bac bao bar bas bat bau bba bbb bbc bbo bbr bbs bbt bbu bca bcb bcc bco bcr bcs bct bcu boa bob boc boo bor bos bot bou bra brb bro brr brs brt bru bsa bsb bsc bso bsr bss bst bsu bta btb btc bto btr bts btt btu bua bub buc buo bur bus but buu c-- caa cab cac cao car cas cat cau cba cbb cbc cbo cbr cbs cbt cbu cca ccb ccc cco ccr ccs cct ccu co- coa cob coc coo cor cos cot cou cra crb crc cro crr crs crt cru csa csb csc cso csr css cst csu cta ctb ctc cto ctr cts ctt ctu cua cub cuc cuo cur cus cut cuu oaa oab oac oao oar oas oat oau ob- oba obb obc obo obr obs obt obu oc- oca ocb occ oco ocr ocs oct ocu oo- ooa oob ooc ooo oor oos oot or- ora orb orc oro orr ors ort oru os- osa osb osc oso osr oss ost osu ot- ota otb otc oto otr ots ott otu ou- oua ouc ouo our ous out ra- raa rab rac rao rar ras rat rau rba rbb rbc rbo rbr rbs rbt rbu rca rcb rcc rco rcr rcs rct rcu roa rob roc roo ror ros rot rou rra rrb rrc rrr rrs rrt rru rsa rsb rsc rso rsr rss rst rsu rta rtb rtc rto rtr rts rtt rtu rua rub ruc ruo rur rus rut ruu saa sab sac sao sar sas sat sau sba sbb sbc sbo sbr sbs sbt sbu sca scb scc sco scr scs sct scu soa sob soc soo sor sos sot sou sr- sra srb src sro srr srs srt ss- ssa ssb ssc sso ssr sss sst ssu sta stb stc sto str sts stt stu sua sub suc suo sur sus sut suu taa tab tac tao tar tas tat tau tba tbb tbc tbo tbr tbs tbt tbu tca tcb tcc tco tcr tcs tct tcu to- toa tob toc too tor tos tot tou tra trb trc tro trr trs trt tru tsa tsb tsc tso tsr tss tst tsu tta ttb ttc tto ttr tts ttt ttu tua tub tuc tuo tur tus tut tuu ua- uaa uab uac uao uar uas uat uau uba ubb ubc ubo ubr ubs ubt ubu uca ucb ucc uco ucr ucs uct ucu uoa uob uoc uoo uor uos uot ur- ura urb urc uro urr urs urt uru usa usb usc uso usr uss ust usu uta utb utc uto utr uts utt utu uua uuc uur uus uut uuu