-er a-a a-b aaa aab aad aae aak aam aao aar ab- aba abb abd abe abk abm abo abr ad- ada adb add ade adk adm ado adr aea aeb aed aee aek aem aeo aer aka akb akd ake akk akm ako akr ama amb amd ame amk amm amo amr aoa aob aod aoe aok aom aoo aor ar- ara arb ard are ark arm aro arr baa bab bad bae bak bam bao bar bba bbb bbd bbe bbk bbm bbo bbr bda bdb bdd bde bdk bdm bdo bdr be- bea beb bed bee bek bem beo ber bka bkb bke bkk bkm bko bkr bma bmb bmd bme bmk bmm bmo bmr boa bob bod boe bok bom boo bor bra brb brd bre brk brm bro brr daa dab dad dae dak dam dao dar dba dbb dbd dbe dbk dbm dbo dbr dda ddb ddd dde ddk ddm ddo ddr de- dea deb ded dee dek dem deo der dka dkb dke dkk dkm dko dkr dma dmb dmd dme dmk dmm dmo dmr doa dob dod doe dok dom doo dor dra drb drd dre drk drm dro drr eaa eab ead eae eak eam eao ear eba ebb ebd ebe ebk ebm ebo ebr ed- eda edb edd ede edk edm edo edr eea eeb eed eee eek eem eeo eer eka ekb ekd eke eko ekr em- ema emb emd eme emk emm emo emr eo- eoa eob eod eoe eok eom eoo eor era erb erd ere erk erm ero err ka- kaa kab kad kae kak kam kao kar kba kbb kbd kbe kbk kbm kbo kbr kda kdb kde kdk kdm kdo kdr ke- kea keb ked kee kek kem keo ker kkb kke kkk kkm kkr kma kmb kmd kme kmk kmm kmo koa kob kod koe kok kom koo kor kra krd krk kro krr m-o m-r maa mab mad mae mak mam mao mar mba mbb mbd mbe mbk mbm mbo mbr mda mdb mdd mde mdk mdm mdo mdr mea meb med mee mek mem meo mer mka mkb mkd mke mkk mkm mko mkr mma mmb mmd mme mmk mmm mmo mmr moa mob mod moe mok mom moo mor mra mrb mrd mre mrk mrm mro mrr oaa oab oad oae oak oam oao oar ob- oba obb obd obe obk obm obo obr oda odb odd ode odm odo odr oea oeb oed oee oem oeo oer oka okb okd oke okk oko okr om- oma omb omd ome omm omo omr oo- ooa oob ood ook oom ooo oor or- ora orb ord ore ork orm oro orr ra- raa rab rad rae rak ram rao rar rba rbb rbd rbe rbk rbm rbo rbr rda rdb rdd rde rdm rdo rdr re- rea reb red ree rek rem reo rer rkb rke rkk rkm rko rma rmb rmd rme rmm rmo rmr roa rob rod roe rok rom roo ror rra rrb rrd rrk rrm rrr