a-a a-b a-c aaa aab aac aag aah aak aao aas ab- aba abb abc abg abh abk abo abs ac- aca acb acc acg ach ack aco acs ag- aga agb agc agg agh agk ago ags aha ahb ahc ahg ahh ahk aho ahs aka akb akc akg akh akk ako aks aoa aob aoc aog aoh aok aoo aos as- asa asb asc asg ash ask aso ass baa bab bac bag bah bak bao bas bba bbb bbc bbg bbh bbk bbo bbs bca bcb bcc bcg bch bck bco bcs bga bgb bgc bgg bgh bgk bgo bgs bha bhb bhc bhg bhh bhk bho bhs bka bkb bkc bkg bkk bko bks boa bob boc bog boh bok boo bos bsa bsb bsc bsg bsh bsk bso bss c-- caa cab cac cag cah cak cao cas cba cbb cbc cbg cbh cbk cbo cbs cca ccb ccc ccg cch cck cco ccs cga cgb cgc cgg cgh cgo cgs ch- cha chb chc chg chh chk cho chs cka ckb ckc ckh cko cks co- coa cob coc cog coh cok coo cos csa csb csc csg csh csk cso css gaa gab gac gag gah gak gao gas gba gbc gbg gbh gbk gbo gbs gca gcb gcc gcg gch gck gco gcs gga ggb ggc ggg ggh ggo ggs gha ghb ghc ghg ghh gho ghs gka gkb gkh gko gks goa gob goc gog goh gok goo gos gsa gsb gsc gsg gsk gso gss haa hab hac hag hah hak hao has hba hbb hbc hbg hbh hbk hbo hbs hca hcb hcc hcg hch hck hco hcs hga hgb hgc hgg hgh hgk hgo hgs hha hhb hhc hhg hhh hhk hho hhs hka hkb hkg hkh hkk hko hks hoa hob hoc hog hoh hok hoo hos hsa hsb hsc hsg hsh hsk hss ka- kaa kab kac kag kah kak kao kas kba kbb kbc kbh kbk kbo kbs kca kcb kcc kcg kch kck kcs kga kgb kgc kgh kgo kgs kha khh khk kho khs kkb kkc kkh kkk kks koa kob koc kog koh kok koo kos ksa ksb ksc ksg ksh ksk kso kss oaa oab oac oag oah oak oao oas ob- oba obb obc obg obh obk obo obs oc- oca ocb occ ocg och ock oco ocs oga ogc ogg ogh ogo ogs oha ohc ohg ohh oho ohs oka okb okc okg okk oko oks oo- ooa oob ooc oog ooh ook ooo oos os- osa osb osc osg osh osk oso oss saa sab sac sag sah sak sao sas sba sbb sbc sbg sbh sbk sbo sbs sca scb scc scg sch sck sco scs sga sgb sgc sgg sgh sgk sgo sgs sh- sha shb shc shg shh shk sho shs sk- ska skb skc skg skh skk sko sks soa sob soc sog soh sok soo sos ss- ssa ssb ssc ssg ssh ssk sso sss