a-a a-b a-i aaa aab aai aak aam aao aas ab- aba abb abi abk abm abo abs ai- aia aib aii aik aim aio ais aka akb aki akk akm ako aks ama amb ami amk amm amo ams aoa aob aoi aok aom aoo aos as- asa asb asi ask asm aso ass baa bab bai bak bam bao bas bba bbb bbi bbk bbm bbo bbs bi- bia bib bii bik bim bio bis bka bkb bkk bkm bko bks bma bmb bmi bmk bmm bmo bms boa bob boi bok bom boo bos bsa bsb bsi bsk bsm bso bss ia- iaa iab iai iam iao ias iba ibb ibi ibk ibm ibo ibs iia iib iii iim iio iis ika ikb iki ikk iko iks im- ima imb imi imm imo ims io- ioa iob ioi iom ioo ios is- isa isb isi isk ism iso iss ka- kaa kab kai kak kam kao kas kba kbb kbi kbk kbm kbo kbs kia kib kii kik kim kio kis kkb kki kkk kkm kks kma kmb kmi kmk kmm kmo kms koa kob koi kok kom koo kos ksa ksb ksi ksk ksm kso kss m-o maa mab mai mak mam mao mas mba mbb mbi mbk mbm mbo mbs mi- mia mib mii mik mim mio mis mka mkb mkk mkm mko mks mma mmb mmi mmk mmm mmo mms moa mob moi mok mom moo mos msa msb msi msk msm mso mss o-i oaa oab oai oak oam oao oas ob- oba obb obi obk obm obo obs oia oib oii oik oim oio ois oka okb oki okk oko oks om- oma omb omi omm omo oms oo- ooa oob ooi ook oom ooo oos os- osa osb osi osk osm oso oss saa sab sai sak sam sao sas sba sbb sbi sbk sbm sbo sbs sia sib sii sik sim sio sis sk- ska skb ski skk skm sko sks sma smb smi smk smm smo sms soa sob soi sok som soo sos ss- ssa ssb ssi ssk ssm sso sss