a-a a-b a-c aaa aab aac aah aar aas ab- aba abb abc abh abr abs ac- aca acb acc ach acr acs aha ahb ahc ahh ahr ahs ar- ara arb arc arh arr ars as- asa asb asc ash asr ass baa bab bac bah bar bas bba bbb bbc bbh bbr bbs bca bcb bcc bch bcr bcs bha bhb bhc bhh bhr bhs bra brb brh brr brs bsa bsb bsc bsh bsr bss c-- caa cab cac cah car cas cba cbb cbc cbh cbr cbs cca ccb ccc cch ccr ccs ch- cha chb chc chh chr chs cra crb crc crh crr crs csa csb csc csh csr css haa hab hac hah har has hba hbb hbc hbh hbr hbs hca hcb hcc hch hcr hcs hha hhb hhc hhh hhr hhs hr- hra hrb hrc hrh hrr hrs hsa hsb hsc hsh hsr hss ra- raa rab rac rah rar ras rba rbb rbc rbh rbr rbs rca rcb rcc rch rcr rcs rh- rha rhb rhc rhh rhr rhs rra rrb rrc rrh rrr rrs rsa rsb rsc rsh rsr rss saa sab sac sah sar sas sba sbb sbc sbh sbr sbs sca scb scc sch scr scs sh- sha shb shc shh shr shs sr- sra srb src srh srr srs ss- ssa ssb ssc ssh ssr sss