a-a a-b aaa aab aad aak aan aao aar aau ab- aba abb abd abk abn abo abr abu ad- ada adb add adk adn ado adr adu aka akb akd akk akn ako akr aku an- ana anb and ank ann ano anr anu aoa aob aod aok aon aoo aor aou ar- ara arb ard ark arn aro arr aru au- aua aub aud auk aun auo aur b-u baa bab bad bak ban bao bar bau bba bbb bbd bbk bbn bbo bbr bbu bda bdb bdd bdk bdo bdr bdu bka bkb bkk bkn bko bkr bna bnb bnd bnk bnn bno bnr bnu boa bob bod bok bon boo bor bou bra brb brd brk brn bro brr bru bua bub bud buk bun buo bur buu daa dab dad dak dan dao dar dau dba dbb dbd dbk dbn dbo dbr dbu dda ddb ddd ddk ddn ddo ddr ddu dka dkb dkk dko dkr dku dna dnb dnd dnk dnn dno dnr doa dob dod dok don doo dor dou dra drb drd drk drn dro drr dru dua dub dud duk dun duo dur ka- kaa kab kad kak kan kao kar kau kba kbb kbd kbk kbn kbo kbr kbu kda kdb kdk kdo kdr kdu kkb kkk kkn kkr kku kn- kna knd knk knn kno knr knu koa kob kod kok kon koo kor kou kra krd krk krn kro krr kru kub kud kuk kun kur kuu naa nab nad nak nan nao nar nau nba nbb nbd nbk nbn nbo nbr nbu nda ndb ndd ndk ndn ndo ndr ndu nka nkk nkn nko nkr nku nna nnb nnk nnn nno nnu no- noa nob nod nok non noo nor nou nra nrb nrd nrk nrn nro nrr nru nua nub nud nuk nun nuo nur nuu oaa oab oad oak oan oao oar oau ob- oba obb obd obk obn obo obr obu oda odb odd odn odo odr odu oka okb okd okk oko okr oku on- ona onb ond onk onn ono onr onu oo- ooa oob ood ook oon ooo oor or- ora orb ord ork orn oro orr oru ou- oua oud ouk oun ouo our ra- raa rab rad rak ran rao rar rau rba rbb rbd rbk rbn rbo rbr rbu rda rdb rdd rdn rdo rdr rdu rkb rkk rko rku rna rnb rnd rnn rno rnr rnu roa rob rod rok ron roo ror rou rra rrb rrd rrk rrn rrr rru rua rub rud ruk run ruo rur ruu ua- uaa uab uad uak uan uao uar uau uba ubb ubk ubn ubo ubr ubu uda udb udd udk udn udo udr udu uka ukb ukk ukn ukr uku un- una unb und unk unn uno unr unu uoa uob uod uok uon uoo uor ur- ura urb urd urk urn uro urr uru uua uun uur uuu