-er a-a a-b aaa aab aae aag aah aao aar aas ab- aba abb abe abg abh abo abr abs aea aeb aee aeg aeh aeo aer aes ag- aga agb age agg agh ago agr ags aha ahb ahe ahg ahh aho ahr ahs aoa aob aoe aog aoh aoo aor aos ar- ara arb are arg arh aro arr ars as- asa asb ase asg ash aso asr ass baa bab bae bag bah bao bar bas bba bbb bbe bbg bbh bbo bbr bbs be- bea beb bee beg beh beo ber bes bga bgb bge bgg bgh bgo bgr bgs bha bhb bhe bhg bhh bho bhr bhs boa bob boe bog boh boo bor bos bra brb bre brg brh bro brr brs bsa bsb bse bsg bsh bso bsr bss eaa eab eae eag eah eao ear eas eba ebb ebe ebg ebh ebo ebr ebs eea eeb eee eeg eeo eer ees ega egb ege egg egh ego egr egs eha ehb ehe ehg ehh eho ehr ehs eo- eoa eob eoe eog eoh eoo eor eos era erb ere erg erh ero err ers es- esa esb ese esg esh eso esr ess gaa gab gae gag gah gao gar gas gba gbe gbg gbh gbo gbr gbs ge- gea geb gee geg geh geo ger ges gga ggb ggg ggh ggo ggr ggs gha ghb ghe ghg ghh gho ghr ghs goa gob goe gog goh goo gor gos gra grb gre grg grh gro grr grs gsa gsb gse gsg gso gsr gss haa hab hae hag hah hao har has hba hbb hbe hbg hbh hbo hbr hbs he- hea heb hee heg heh heo her hes hga hgb hge hgg hgh hgo hgr hgs hha hhb hhe hhg hhh hho hhr hhs hoa hob hoe hog hoh hoo hor hos hr- hra hrb hre hrg hrh hro hrr hrs hsa hsb hse hsg hsh hsr hss oaa oab oae oag oah oao oar oas ob- oba obb obe obg obh obo obr obs oea oeb oee oeg oeh oeo oer oes oga oge ogg ogh ogo ogs oha ohe ohg ohh oho ohr ohs oo- ooa oob oog ooh ooo oor oos or- ora orb ore org orh oro orr ors os- osa osb ose osg osh oso osr oss ra- raa rab rae rag rah rao rar ras rba rbb rbe rbg rbh rbo rbr rbs re- rea reb ree reg reh reo rer res rga rgb rge rgg rgh rgo rgr rgs rh- rha rhb rhe rhg rhh rho rhr rhs roa rob roe rog roh roo ror ros rra rrb rrg rrh rrr rrs rsa rsb rse rsg rsh rso rsr rss saa sab sae sag sah sao sar sas sba sbb sbe sbg sbh sbo sbr sbs se- sea seb see seg seh seo ser ses sga sgb sge sgg sgh sgo sgr sgs sh- sha shb she shg shh sho shr shs soa sob soe sog soh soo sor sos sr- sra srb sre srg srh sro srr srs ss- ssa ssb sse ssg ssh sso ssr sss