a-a a-b a-c aaa aab aac aah aak aan aar aas ab- aba abb abc abh abk abn abr abs ac- aca acb acc ach ack acn acr acs aha ahb ahc ahh ahk ahn ahr ahs aka akb akc akh akk akn akr aks an- ana anb anc anh ank ann anr ans ar- ara arb arc arh ark arn arr ars as- asa asb asc ash ask asn asr ass baa bab bac bah bak ban bar bas bba bbb bbc bbh bbk bbn bbr bbs bca bcb bcc bch bck bcn bcr bcs bha bhb bhc bhh bhk bhr bhs bka bkb bkc bkk bkn bkr bks bna bnb bnc bnk bnn bnr bns bra brb brh brk brn brr brs bsa bsb bsc bsh bsk bsn bsr bss c-- caa cab cac cah cak can car cas cba cbb cbc cbh cbk cbn cbr cbs cca ccb ccc cch cck ccn ccr ccs ch- cha chb chc chh chk chn chr chs cka ckb ckc ckh cks cn- cna cnb cnc cnh cnn cnr cns cra crb crc crh crk crn crr crs csa csb csc csh csk csn csr css haa hab hac hah hak han har has hba hbb hbc hbh hbk hbn hbr hbs hca hcb hcc hch hck hcn hcr hcs hha hhb hhc hhh hhk hhn hhr hhs hka hkb hkh hkk hkn hkr hks hna hnb hnc hnh hnk hnn hns hr- hra hrb hrc hrh hrk hrn hrr hrs hsa hsb hsc hsh hsk hsn hsr hss ka- kaa kab kac kah kak kan kar kas kba kbb kbc kbh kbk kbn kbr kbs kca kcb kcc kch kck kcn kcr kcs kha khh khk khn khr khs kkb kkc kkh kkk kkn kkr kks kn- kna knc knk knn knr kra krc krk krn krr krs ksa ksb ksc ksh ksk ksn ksr kss naa nab nac nah nak nan nar nas nba nbb nbc nbk nbn nbr nbs nca ncb ncc nch nck ncn ncr ncs nha nhb nhc nhh nhk nhn nhr nhs nka nkc nkk nkn nkr nks nna nnb nnc nnh nnk nnn nns nra nrb nrc nrk nrn nrr nrs nsa nsb nsc nsh nsk nsn nsr nss ra- raa rab rac rah rak ran rar ras rba rbb rbc rbh rbk rbn rbr rbs rca rcb rcc rch rcn rcr rcs rh- rha rhb rhc rhh rhn rhr rhs rkb rkc rkk rks rna rnb rnc rnh rnn rnr rns rra rrb rrc rrh rrk rrn rrr rrs rsa rsb rsc rsh rsk rsn rsr rss saa sab sac sah sak san sar sas sba sbb sbc sbh sbk sbn sbr sbs sca scb scc sch sck scn scr scs sh- sha shb shc shh shk shn shr shs sk- ska skb skc skh skk skr sks sna snb snc snk snn snr sns sr- sra srb src srh srk srn srr srs ss- ssa ssb ssc ssh ssk ssn ssr sss