-er a-a a-b a-c aaa aab aac aae aah aak aar aas ab- aba abb abc abe abh abk abr abs ac- aca acb acc ace ach ack acr acs aea aeb aec aee aeh aek aer aes aha ahb ahc ahe ahh ahk ahr ahs aka akb akc ake akh akk akr aks ar- ara arb arc are arh ark arr ars as- asa asb asc ase ash ask asr ass baa bab bac bae bah bak bar bas bba bbb bbc bbe bbh bbk bbr bbs bca bcb bcc bce bch bck bcr bcs be- bea beb bec bee beh bek ber bes bha bhb bhc bhe bhh bhk bhr bhs bka bkb bkc bke bkk bkr bks bra brb bre brh brk brr brs bsa bsb bsc bse bsh bsk bsr bss c-- caa cab cac cae cah cak car cas cba cbb cbc cbe cbh cbk cbr cbs cca ccb ccc cce cch cck ccr ccs ce- cea ceb cec cee ceh cek cer ces ch- cha chb chc che chh chk chr chs cka ckb ckc ckh cks cra crb crc cre crh crk crr crs csa csb csc cse csh csk csr css eaa eab eac eae eah eak ear eas eba ebb ebc ebe ebh ebk ebr ebs ec- eca ecb ecc ece ech eck ecr ecs eea eeb eec eee eek eer ees eha ehb ehc ehe ehh ehr ehs eka ekb ekc eke ekh ekr eks era erb erc ere erh erk err ers es- esa esb esc ese esh esk esr ess haa hab hac hae hah hak har has hba hbb hbc hbe hbh hbk hbr hbs hca hcb hcc hce hch hck hcr hcs he- hea heb hec hee heh hek her hes hha hhb hhc hhe hhh hhk hhr hhs hka hkb hkh hkk hkr hks hr- hra hrb hrc hre hrh hrk hrr hrs hsa hsb hsc hse hsh hsk hsr hss ka- kaa kab kac kae kah kak kar kas kba kbb kbc kbe kbh kbk kbr kbs kca kcb kcc kce kch kck kcr kcs ke- kea keb kec kee keh kek ker kes kha khe khh khk khr khs kkb kkc kke kkh kkk kkr kks kra krc krk krr krs ksa ksb ksc kse ksh ksk ksr kss ra- raa rab rac rae rah rak rar ras rba rbb rbc rbe rbh rbk rbr rbs rca rcb rcc rce rch rcr rcs re- rea reb rec ree reh rek rer res rh- rha rhb rhc rhe rhh rhr rhs rkb rkc rke rkk rks rra rrb rrc rrh rrk rrr rrs rsa rsb rsc rse rsh rsk rsr rss saa sab sac sae sah sak sar sas sba sbb sbc sbe sbh sbk sbr sbs sca scb scc sce sch sck scr scs se- sea seb sec see seh sek ser ses sh- sha shb shc she shh shk shr shs sk- ska skb skc ske skh skk skr sks sr- sra srb src sre srh srk srr srs ss- ssa ssb ssc sse ssh ssk ssr sss