a-a a-b a-i aaa aab aad aai aak aao aar ab- aba abb abd abi abk abo abr ad- ada adb add adi adk ado adr ai- aia aib aid aii aik aio air aka akb akd aki akk ako akr aoa aob aod aoi aok aoo aor ar- ara arb ard ari ark aro arr baa bab bad bai bak bao bar bba bbb bbd bbi bbk bbo bbr bda bdb bdd bdi bdk bdo bdr bi- bia bib bid bii bik bio bir bka bkb bkk bko bkr boa bob bod boi bok boo bor bra brb brd bri brk bro brr daa dab dad dai dak dao dar dba dbb dbd dbi dbk dbo dbr dda ddb ddd ddi ddk ddo ddr di- dia dib did dii dik dio dir dka dkb dki dkk dko dkr doa dob dod doi dok doo dor dra drb drd dri drk dro drr i-d ia- iaa iab iad iai iao iar iba ibb ibd ibi ibk ibo ibr ida idb idd idi idk ido idr iia iib iid iii iio iir ika ikb iki ikk iko ikr io- ioa iob iod ioi ioo ior ir- ira irb ird iri irk iro irr ka- kaa kab kad kai kak kao kar kba kbb kbd kbi kbk kbo kbr kda kdb kdk kdo kdr kia kib kid kii kik kio kir kkb kki kkk kkr koa kob kod koi kok koo kor kra krd kri krk kro krr o-i oaa oab oad oai oak oao oar ob- oba obb obd obi obk obo obr oda odb odd odi odo odr oia oib oid oii oik oio oir oka okb okd oki okk oko okr oo- ooa oob ood ooi ook ooo oor or- ora orb ord ori ork oro orr ra- raa rab rad rai rak rao rar rba rbb rbd rbi rbk rbo rbr rda rdb rdd rdi rdo rdr ria rib rid rii rik rio rir rkb rkk rko roa rob rod roi rok roo ror rra rrb rrd rri rrk rrr