a-a a-b a-c aaa aab aac aah aak aar aas ab- aba abb abc abh abk abr abs ac- aca acb acc ach ack acr acs aha ahb ahc ahh ahk ahr ahs aka akb akc akh akk akr aks ar- ara arb arc arh ark arr ars as- asa asb asc ash ask asr ass baa bab bac bah bak bar bas bba bbb bbc bbh bbk bbr bbs bca bcb bcc bch bck bcr bcs bha bhb bhc bhh bhk bhr bhs bka bkb bkc bkk bkr bks bra brb brh brk brr brs bsa bsb bsc bsh bsk bsr bss c-- caa cab cac cah cak car cas cba cbb cbc cbh cbk cbr cbs cca ccb ccc cch cck ccr ccs ch- cha chb chc chh chk chr chs cka ckb ckc ckh cks cra crb crc crh crk crr crs csa csb csc csh csk csr css haa hab hac hah hak har has hba hbb hbc hbh hbk hbr hbs hca hcb hcc hch hck hcr hcs hha hhb hhc hhh hhk hhr hhs hka hkb hkh hkk hkr hks hr- hra hrb hrc hrh hrk hrr hrs hsa hsb hsc hsh hsk hsr hss ka- kaa kab kac kah kak kar kas kba kbb kbc kbh kbk kbr kbs kca kcb kcc kch kck kcr kcs kha khh khk khr khs kkb kkc kkh kkk kkr kks kra krc krk krr krs ksa ksb ksc ksh ksk ksr kss ra- raa rab rac rah rak rar ras rba rbb rbc rbh rbk rbr rbs rca rcb rcc rch rcr rcs rh- rha rhb rhc rhh rhr rhs rkb rkc rkk rks rra rrb rrc rrh rrk rrr rrs rsa rsb rsc rsh rsk rsr rss saa sab sac sah sak sar sas sba sbb sbc sbh sbk sbr sbs sca scb scc sch sck scr scs sh- sha shb shc shh shk shr shs sk- ska skb skc skh skk skr sks sr- sra srb src srh srk srr srs ss- ssa ssb ssc ssh ssk ssr sss