-er a-a a-b aaa aab aae aah aak aao aar aas ab- aba abb abe abh abk abo abr abs aea aeb aee aeh aek aeo aer aes aha ahb ahe ahh ahk aho ahr ahs aka akb ake akh akk ako akr aks aoa aob aoe aoh aok aoo aor aos ar- ara arb are arh ark aro arr ars as- asa asb ase ash ask aso asr ass baa bab bae bah bak bao bar bas bba bbb bbe bbh bbk bbo bbr bbs be- bea beb bee beh bek beo ber bes bha bhb bhe bhh bhk bho bhr bhs bka bkb bke bkk bko bkr bks boa bob boe boh bok boo bor bos bra brb bre brh brk bro brr brs bsa bsb bse bsh bsk bso bsr bss eaa eab eae eah eak eao ear eas eba ebb ebe ebh ebk ebo ebr ebs eea eeb eee eek eeo eer ees eha ehb ehe ehh eho ehr ehs eka ekb eke ekh eko ekr eks eo- eoa eob eoe eoh eok eoo eor eos era erb ere erh erk ero err ers es- esa esb ese esh esk eso esr ess haa hab hae hah hak hao har has hba hbb hbe hbh hbk hbo hbr hbs he- hea heb hee heh hek heo her hes hha hhb hhe hhh hhk hho hhr hhs hka hkb hkh hkk hko hkr hks hoa hob hoe hoh hok hoo hor hos hr- hra hrb hre hrh hrk hro hrr hrs hsa hsb hse hsh hsk hsr hss ka- kaa kab kae kah kak kao kar kas kba kbb kbe kbh kbk kbo kbr kbs ke- kea keb kee keh kek keo ker kes kha khe khh khk kho khr khs kkb kke kkh kkk kkr kks koa kob koe koh kok koo kor kos kra krk kro krr krs ksa ksb kse ksh ksk kso ksr kss oaa oab oae oah oak oao oar oas ob- oba obb obe obh obk obo obr obs oea oeb oee oeh oeo oer oes oha ohe ohh oho ohr ohs oka okb oke okk oko okr oks oo- ooa oob ooh ook ooo oor oos or- ora orb ore orh ork oro orr ors os- osa osb ose osh osk oso osr oss ra- raa rab rae rah rak rao rar ras rba rbb rbe rbh rbk rbo rbr rbs re- rea reb ree reh rek reo rer res rh- rha rhb rhe rhh rho rhr rhs rkb rke rkk rko rks roa rob roe roh rok roo ror ros rra rrb rrh rrk rrr rrs rsa rsb rse rsh rsk rso rsr rss saa sab sae sah sak sao sar sas sba sbb sbe sbh sbk sbo sbr sbs se- sea seb see seh sek seo ser ses sh- sha shb she shh shk sho shr shs sk- ska skb ske skh skk sko skr sks soa sob soe soh sok soo sor sos sr- sra srb sre srh srk sro srr srs ss- ssa ssb sse ssh ssk sso ssr sss