a-a a-b aaa aab aad aak aan aao aar aas ab- aba abb abd abk abn abo abr abs ad- ada adb add adk adn ado adr ads aka akb akd akk akn ako akr aks an- ana anb and ank ann ano anr ans aoa aob aod aok aon aoo aor aos ar- ara arb ard ark arn aro arr ars as- asa asb asd ask asn aso asr ass baa bab bad bak ban bao bar bas bba bbb bbd bbk bbn bbo bbr bbs bda bdb bdd bdk bdo bdr bds bka bkb bkk bkn bko bkr bks bna bnb bnd bnk bnn bno bnr bns boa bob bod bok bon boo bor bos bra brb brd brk brn bro brr brs bsa bsb bsd bsk bsn bso bsr bss daa dab dad dak dan dao dar das dba dbb dbd dbk dbn dbo dbr dbs dda ddb ddd ddk ddn ddo ddr dds dka dkb dkk dko dkr dks dna dnb dnd dnk dnn dno dnr dns doa dob dod dok don doo dor dos dra drb drd drk drn dro drr drs dsa dsb dsd dsk dsn dso dsr dss ka- kaa kab kad kak kan kao kar kas kba kbb kbd kbk kbn kbo kbr kbs kda kdb kdk kdo kdr kds kkb kkk kkn kkr kks kn- kna knd knk knn kno knr koa kob kod kok kon koo kor kos kra krd krk krn kro krr krs ksa ksb ksd ksk ksn kso ksr kss naa nab nad nak nan nao nar nas nba nbb nbd nbk nbn nbo nbr nbs nda ndb ndd ndk ndn ndo ndr nds nka nkk nkn nko nkr nks nna nnb nnk nnn nno nns no- noa nob nod nok non noo nor nos nra nrb nrd nrk nrn nro nrr nrs nsa nsb nsd nsk nsn nso nsr nss oaa oab oad oak oan oao oar oas ob- oba obb obd obk obn obo obr obs oda odb odd odn odo odr ods oka okb okd okk oko okr oks on- ona onb ond onk onn ono onr ons oo- ooa oob ood ook oon ooo oor oos or- ora orb ord ork orn oro orr ors os- osa osb osd osk osn oso osr oss ra- raa rab rad rak ran rao rar ras rba rbb rbd rbk rbn rbo rbr rbs rda rdb rdd rdn rdo rdr rds rkb rkk rko rks rna rnb rnd rnn rno rnr rns roa rob rod rok ron roo ror ros rra rrb rrd rrk rrn rrr rrs rsa rsb rsd rsk rsn rso rsr rss saa sab sad sak san sao sar sas sba sbb sbd sbk sbn sbo sbr sbs sda sdb sdd sdk sdn sdo sdr sds sk- ska skb skd skk sko skr sks sna snb snd snk snn sno snr sns soa sob sod sok son soo sor sos sr- sra srb srd srk srn sro srr srs ss- ssa ssb ssd ssk ssn sso ssr sss