a-a a-b aaa aab aak aam aan aao aar aas ab- aba abb abk abm abn abo abr abs aka akb akk akm akn ako akr aks ama amb amk amm amn amo amr ams an- ana anb ank anm ann ano anr ans aoa aob aok aom aon aoo aor aos ar- ara arb ark arm arn aro arr ars as- asa asb ask asm asn aso asr ass baa bab bak bam ban bao bar bas bba bbb bbk bbm bbn bbo bbr bbs bka bkb bkk bkm bkn bko bkr bks bma bmb bmk bmm bmn bmo bmr bms bna bnb bnk bnn bno bnr bns boa bob bok bom bon boo bor bos bra brb brk brm brn bro brr brs bsa bsb bsk bsm bsn bso bsr bss ka- kaa kab kak kam kan kao kar kas kba kbb kbk kbm kbn kbo kbr kbs kkb kkk kkm kkn kkr kks kma kmb kmk kmm kmo kms kn- kna knk knm knn kno knr koa kob kok kom kon koo kor kos kra krk krn kro krr krs ksa ksb ksk ksm ksn kso ksr kss m-o m-r maa mab mak mam man mao mar mas mba mbb mbk mbm mbo mbr mbs mka mkb mkk mkm mkn mko mkr mks mma mmb mmk mmm mmn mmo mmr mms mna mnb mnk mnm mnn mno mnr mns moa mob mok mom mon moo mor mos mra mrb mrk mrm mrn mro mrr mrs msa msb msk msm msn mso msr mss naa nab nak nam nan nao nar nas nba nbb nbk nbm nbn nbo nbr nbs nka nkk nkm nkn nko nkr nks nma nmb nmk nmm nmn nmo nmr nms nna nnb nnk nnm nnn nno nns no- noa nob nok nom non noo nor nos nra nrb nrk nrm nrn nro nrr nrs nsa nsb nsk nsm nsn nso nsr nss oaa oab oak oam oan oao oar oas ob- oba obb obk obm obn obo obr obs oka okb okk oko okr oks om- oma omb omm omn omo omr oms on- ona onb onk onn ono onr ons oo- ooa oob ook oom oon ooo oor oos or- ora orb ork orm orn oro orr ors os- osa osb osk osm osn oso osr oss ra- raa rab rak ram ran rao rar ras rba rbb rbk rbm rbn rbo rbr rbs rkb rkk rkm rko rks rma rmb rmm rmn rmo rmr rms rna rnb rnm rnn rno rnr rns roa rob rok rom ron roo ror ros rra rrb rrk rrm rrn rrr rrs rsa rsb rsk rsm rsn rso rsr rss saa sab sak sam san sao sar sas sba sbb sbk sbm sbn sbo sbr sbs sk- ska skb skk skm sko skr sks sma smb smk smm smn smo smr sms sna snb snk snm snn sno snr sns soa sob sok som son soo sor sos sr- sra srb srk srm srn sro srr srs ss- ssa ssb ssk ssm ssn sso ssr sss