a-a a-b aaa aab aae aak aam aao aas aax ab- aba abb abe abk abm abo abs abx aea aeb aee aek aem aeo aes aex aka akb ake akk akm ako aks ama amb ame amk amm amo ams amx aoa aob aoe aok aom aoo aos aox as- asa asb ase ask asm aso ass asx ax- axa axe axk axm axo axs axx baa bab bae bak bam bao bas bax bba bbb bbe bbk bbm bbo bbs bbx be- bea beb bee bek bem beo bes bex bka bkb bke bkk bkm bko bks bkx bma bmb bme bmk bmm bmo bms bmx boa bob boe bok bom boo bos box bsa bsb bse bsk bsm bso bss bsx bxb bxm bxo bxx eaa eab eae eak eam eao eas eax eba ebb ebe ebk ebm ebo ebs ebx eea eeb eee eek eem eeo ees eex eka ekb eke eko eks em- ema emb eme emk emm emo ems emx eo- eoa eob eoe eok eom eoo eos es- esa esb ese esk esm eso ess esx ex- exa exe exo exs exx ka- kaa kab kae kak kam kao kas kax kba kbb kbe kbk kbm kbo kbs kbx ke- kea keb kee kek kem keo kes kex kkb kke kkk kkm kks kma kmb kme kmk kmm kmo kms koa kob koe kok kom koo kos ksa ksb kse ksk ksm kso kss kxm kxo m-o maa mab mae mak mam mao mas max mba mbb mbe mbk mbm mbo mbs mbx mea meb mee mek mem meo mes mex mka mkb mke mkk mkm mko mks mkx mma mmb mme mmk mmm mmo mms mmx moa mob moe mok mom moo mos mox msa msb mse msk msm mso mss msx mxa mxs oaa oab oae oak oam oao oas oax ob- oba obb obe obk obm obo obs obx oea oeb oee oem oeo oes oex oka okb oke okk oko oks om- oma omb ome omm omo oms omx oo- ooa oob ook oom ooo oos oox os- osa osb ose osk osm oso oss osx ox- oxa oxb oxo oxx saa sab sae sak sam sao sas sax sba sbb sbe sbk sbm sbo sbs sbx se- sea seb see sek sem seo ses sex sk- ska skb ske skk skm sko sks skx sma smb sme smk smm smo sms smx soa sob soe sok som soo sos sox ss- ssa ssb sse ssk ssm sso sss ssx sxm sxs xaa xak xam xas xbe xbx xee xem xes xex xkb xke xks xma xmk xmm xmo xms xmx xoa xok xom xoo xos xox xsa xsb xsm xss xxo xxx