-th a-a a-b a-c a-t aaa aab aac aah aar aas aat ab- aba abb abc abh abr abs abt ac- aca acb acc ach acr acs act aha ahb ahc ahh ahr ahs aht ar- ara arb arc arh arr ars art as- asa asb asc ash asr ass ast at- ata atb atc ath atr ats att baa bab bac bah bar bas bat bba bbb bbc bbh bbr bbs bbt bca bcb bcc bch bcr bcs bct bha bhb bhc bhh bhr bhs bht bra brb brh brr brs brt bsa bsb bsc bsh bsr bss bst bta btb btc bth btr bts btt c-- caa cab cac cah car cas cat cba cbb cbc cbh cbr cbs cbt cca ccb ccc cch ccr ccs cct ch- cha chb chc chh chr chs cht cra crb crc crh crr crs crt csa csb csc csh csr css cst cta ctb ctc cth ctr cts ctt haa hab hac hah har has hat hba hbb hbc hbh hbr hbs hbt hca hcb hcc hch hcr hcs hct hha hhb hhc hhh hhr hhs hht hr- hra hrb hrc hrh hrr hrs hrt hsa hsb hsc hsh hsr hss hst hta htb htc hth htr hts htt ra- raa rab rac rah rar ras rat rba rbb rbc rbh rbr rbs rbt rca rcb rcc rch rcr rcs rct rh- rha rhb rhc rhh rhr rhs rht rra rrb rrc rrh rrr rrs rrt rsa rsb rsc rsh rsr rss rst rta rtb rtc rtr rts rtt saa sab sac sah sar sas sat sba sbb sbc sbh sbr sbs sbt sca scb scc sch scr scs sct sh- sha shb shc shh shr shs sht sr- sra srb src srh srr srs srt ss- ssa ssb ssc ssh ssr sss sst sta stb stc sth str sts stt taa tab tac tah tar tas tat tba tbb tbc tbh tbr tbs tbt tca tcb tcc tch tcr tcs tct th- tha thb thc thh thr ths tht tra trb trc trh trr trs trt tsa tsb tsc tsh tsr tss tst tta ttb ttc tth ttr tts ttt