a-a a-b aaa aab aaj aak aan aao aar aas ab- aba abb abj abk abn abo abr abs aja ajb ajj ajk ajn ajo ajr ajs aka akb akj akk akn ako akr aks an- ana anb anj ank ann ano anr ans aoa aob aoj aok aon aoo aor aos ar- ara arb arj ark arn aro arr ars as- asa asb asj ask asn aso asr ass baa bab baj bak ban bao bar bas bba bbb bbk bbn bbo bbr bbs bja bjj bjk bjn bjr bjs bka bkb bkk bkn bko bkr bks bna bnb bnj bnk bnn bno bnr bns boa bob boj bok bon boo bor bos bra brb brj brk brn bro brr brs bsa bsb bsj bsk bsn bso bsr bss jaa jab jaj jak jan jao jar jas jba jbj jbk jbo jbr jbs jja jjb jjj jjk jjr jjs jka jkb jkk jkn jko jkr jks jna jnj jnn jno jnr jns joa job joj jok jon joo jor jos jra jrb jrk jrn jro jrr jrs jsa jsb jsj jsk jsn jso jsr jss ka- kaa kab kaj kak kan kao kar kas kba kbb kbk kbn kbo kbr kbs kjb kjr kjs kkb kkk kkn kkr kks kn- kna knk knn kno knr koa kob kok kon koo kor kos kra krk krn kro krr krs ksa ksb ksk ksn kso ksr kss naa nab naj nak nan nao nar nas nba nbb nbk nbn nbo nbr nbs nja njk njn njs nka nkj nkk nkn nko nkr nks nna nnb nnk nnn nno nns no- noa nob noj nok non noo nor nos nra nrb nrj nrk nrn nro nrr nrs nsa nsb nsk nsn nso nsr nss oaa oab oaj oak oan oao oar oas ob- oba obb obj obk obn obo obr obs oja ojb ojo ojs oka okb okj okk oko okr oks on- ona onb onj onk onn ono onr ons oo- ooa oob ook oon ooo oor oos or- ora orb ork orn oro orr ors os- osa osb osj osk osn oso osr oss ra- raa rab raj rak ran rao rar ras rba rbb rbk rbn rbo rbr rbs rja rjk rjr rkb rkk rko rks rna rnb rnn rno rnr rns roa rob roj rok ron roo ror ros rra rrb rrk rrn rrr rrs rsa rsb rsj rsk rsn rso rsr rss saa sab saj sak san sao sar sas sba sbb sbj sbk sbn sbo sbr sbs sja sjb sjj sjk sjr sjs sk- ska skb skj skk sko skr sks sna snb snj snk snn sno snr sns soa sob soj sok son soo sor sos sr- sra srb srj srk srn sro srr srs ss- ssa ssb ssj ssk ssn sso ssr sss