a-a a-b a-c aaa aab aac aae aah aak aao aas ab- aba abb abc abe abh abk abo abs ac- aca acb acc ace ach ack aco acs aea aeb aec aee aeh aek aeo aes aha ahb ahc ahe ahh ahk aho ahs aka akb akc ake akh akk ako aks aoa aob aoc aoe aoh aok aoo aos as- asa asb asc ase ash ask aso ass baa bab bac bae bah bak bao bas bba bbb bbc bbe bbh bbk bbo bbs bca bcb bcc bce bch bck bco bcs be- bea beb bec bee beh bek beo bes bha bhb bhc bhe bhh bhk bho bhs bka bkb bkc bke bkk bko bks boa bob boc boe boh bok boo bos bsa bsb bsc bse bsh bsk bso bss c-- caa cab cac cae cah cak cao cas cba cbb cbc cbe cbh cbk cbo cbs cca ccb ccc cce cch cck cco ccs ce- cea ceb cec cee ceh cek ceo ces ch- cha chb chc che chh chk cho chs cka ckb ckc ckh cko cks co- coa cob coc coe coh cok coo cos csa csb csc cse csh csk cso css eaa eab eac eae eah eak eao eas eba ebb ebc ebe ebh ebk ebo ebs ec- eca ecb ecc ece ech eck eco ecs eea eeb eec eee eek eeo ees eha ehb ehc ehe ehh eho ehs eka ekb ekc eke ekh eko eks eo- eoa eob eoc eoe eoh eok eoo eos es- esa esb esc ese esh esk eso ess haa hab hac hae hah hak hao has hba hbb hbc hbe hbh hbk hbo hbs hca hcb hcc hce hch hck hco hcs he- hea heb hec hee heh hek heo hes hha hhb hhc hhe hhh hhk hho hhs hka hkb hkh hkk hko hks hoa hob hoc hoe hoh hok hoo hos hsa hsb hsc hse hsh hsk hss ka- kaa kab kac kae kah kak kao kas kba kbb kbc kbe kbh kbk kbo kbs kca kcb kcc kce kch kck kcs ke- kea keb kec kee keh kek keo kes kha khe khh khk kho khs kkb kkc kke kkh kkk kks koa kob koc koe koh kok koo kos ksa ksb ksc kse ksh ksk kso kss oaa oab oac oae oah oak oao oas ob- oba obb obc obe obh obk obo obs oc- oca ocb occ och ock oco ocs oea oeb oec oee oeh oeo oes oha ohc ohe ohh oho ohs oka okb okc oke okk oko oks oo- ooa oob ooc ooh ook ooo oos os- osa osb osc ose osh osk oso oss saa sab sac sae sah sak sao sas sba sbb sbc sbe sbh sbk sbo sbs sca scb scc sce sch sck sco scs se- sea seb sec see seh sek seo ses sh- sha shb shc she shh shk sho shs sk- ska skb skc ske skh skk sko sks soa sob soc soe soh sok soo sos ss- ssa ssb ssc sse ssh ssk sso sss