a-a a-b aaa aab aad aak aan aao aar ab- aba abb abd abk abn abo abr ad- ada adb add adk adn ado adr aka akb akd akk akn ako akr an- ana anb and ank ann ano anr aoa aob aod aok aon aoo aor ar- ara arb ard ark arn aro arr baa bab bad bak ban bao bar bba bbb bbd bbk bbn bbo bbr bda bdb bdd bdk bdo bdr bka bkb bkk bkn bko bkr bna bnb bnd bnk bnn bno bnr boa bob bod bok bon boo bor bra brb brd brk brn bro brr daa dab dad dak dan dao dar dba dbb dbd dbk dbn dbo dbr dda ddb ddd ddk ddn ddo ddr dka dkb dkk dko dkr dna dnb dnd dnk dnn dno dnr doa dob dod dok don doo dor dra drb drd drk drn dro drr ka- kaa kab kad kak kan kao kar kba kbb kbd kbk kbn kbo kbr kda kdb kdk kdo kdr kkb kkk kkn kkr kn- kna knd knk knn kno knr koa kob kod kok kon koo kor kra krd krk krn kro krr naa nab nad nak nan nao nar nba nbb nbd nbk nbn nbo nbr nda ndb ndd ndk ndn ndo ndr nka nkk nkn nko nkr nna nnb nnk nnn nno no- noa nob nod nok non noo nor nra nrb nrd nrk nrn nro nrr oaa oab oad oak oan oao oar ob- oba obb obd obk obn obo obr oda odb odd odn odo odr oka okb okd okk oko okr on- ona onb ond onk onn ono onr oo- ooa oob ood ook oon ooo oor or- ora orb ord ork orn oro orr ra- raa rab rad rak ran rao rar rba rbb rbd rbk rbn rbo rbr rda rdb rdd rdn rdo rdr rkb rkk rko rna rnb rnd rnn rno rnr roa rob rod rok ron roo ror rra rrb rrd rrk rrn rrr