a-a a-b aaa aab aad aak aam aao aar ab- aba abb abd abk abm abo abr ad- ada adb add adk adm ado adr aka akb akd akk akm ako akr ama amb amd amk amm amo amr aoa aob aod aok aom aoo aor ar- ara arb ard ark arm aro arr baa bab bad bak bam bao bar bba bbb bbd bbk bbm bbo bbr bda bdb bdd bdk bdm bdo bdr bka bkb bkk bkm bko bkr bma bmb bmd bmk bmm bmo bmr boa bob bod bok bom boo bor bra brb brd brk brm bro brr daa dab dad dak dam dao dar dba dbb dbd dbk dbm dbo dbr dda ddb ddd ddk ddm ddo ddr dka dkb dkk dkm dko dkr dma dmb dmd dmk dmm dmo dmr doa dob dod dok dom doo dor dra drb drd drk drm dro drr ka- kaa kab kad kak kam kao kar kba kbb kbd kbk kbm kbo kbr kda kdb kdk kdm kdo kdr kkb kkk kkm kkr kma kmb kmd kmk kmm kmo koa kob kod kok kom koo kor kra krd krk kro krr m-o m-r maa mab mad mak mam mao mar mba mbb mbd mbk mbm mbo mbr mda mdb mdd mdk mdm mdo mdr mka mkb mkd mkk mkm mko mkr mma mmb mmd mmk mmm mmo mmr moa mob mod mok mom moo mor mra mrb mrd mrk mrm mro mrr oaa oab oad oak oam oao oar ob- oba obb obd obk obm obo obr oda odb odd odm odo odr oka okb okd okk oko okr om- oma omb omd omm omo omr oo- ooa oob ood ook oom ooo oor or- ora orb ord ork orm oro orr ra- raa rab rad rak ram rao rar rba rbb rbd rbk rbm rbo rbr rda rdb rdd rdm rdo rdr rkb rkk rkm rko rma rmb rmd rmm rmo rmr roa rob rod rok rom roo ror rra rrb rrd rrk rrm rrr