-er a-a a-b aaa aab aae aaf aak aan aao aar aav ab- aba abb abe abf abk abn abo abr abv aea aeb aee aef aek aen aeo aer aev af- afa afb afe aff afk afn afo afr afv aka akb ake akk akn ako akr akv an- ana anb ane anf ank ann ano anr anv aoa aob aoe aof aok aon aoo aor aov ar- ara arb are arf ark arn aro arr arv av- ava avb ave avf avk avn avo avr baa bab bae baf bak ban bao bar bav bba bbb bbe bbf bbk bbn bbo bbr be- bea beb bee bef bek ben beo ber bev bfa bfb bfe bff bfn bfo bfr bfv bka bkb bke bkf bkk bkn bko bkr bkv bna bnb bne bnf bnk bnn bno bnr bnv boa bob boe bof bok bon boo bor bov bra brb bre brf brk brn bro brr brv bva bvb bve bvk bvn bvo bvr bvv eaa eab eae eaf eak ean eao ear eav eba ebb ebe ebf ebk ebn ebo ebr ebv eea eeb eee eef eek een eeo eer eev ef- efa efb efe eff efo efr eka ekb eke ekf eko ekr ekv en- ena enb ene enf enk enn eno enr env eo- eoa eob eoe eof eok eon eoo eor era erb ere erf erk ern ero err erv eva evb eve evf evn evo evr evv faa fab fae faf fak fan fao far fav fba fbb fbe fbf fbk fbn fbo fbr fea feb fee fef fek fen feo fer fev ffa ffe fff ffk ffn ffo ffr ffv fka fkb fkf fkk fna fnb fne fnf fnk fnn fnr fnv foa fob foe fof fok fon foo for fra frb fre frf frk frn fro frr fva fvk ka- kaa kab kae kaf kak kan kao kar kav kba kbb kbe kbf kbk kbn kbo kbr ke- kea keb kee kef kek ken keo ker kev kfa kff kfo kkb kke kkk kkn kkr kkv kn- kna kne knf knk knn kno knr koa kob koe kof kok kon koo kor kra krf krk krn kro krr krv kva kvb kvk kvn kvo kvr kvv naa nab nae naf nak nan nao nar nav nba nbb nbe nbf nbk nbn nbo nbr nbv ne- nea neb nee nef nek nen neo ner nev nfa nfb nfe nff nfk nfn nfo nfr nfv nka nke nkf nkk nkn nko nkr nna nnb nne nnf nnk nnn nno nnv no- noa nob noe nof nok non noo nor nov nra nrb nre nrf nrk nrn nro nrr nrv nva nvb nve nvk nvn nvv oaa oab oae oaf oak oan oao oar oav ob- oba obb obe obf obk obn obo obr obv oea oeb oee oef oen oeo oer of- ofa ofb ofe off ofn ofo ofr ofv oka okb oke okk oko okr on- ona onb one onf onk onn ono onr oo- ooa oob oof ook oon ooo oor oov or- ora orb ore orf ork orn oro orr orv ov- ova ovb ove ovf ovo ovv ra- raa rab rae raf rak ran rao rar rav rba rbb rbe rbf rbk rbn rbo rbr re- rea reb ree ref rek ren reo rer rev rfa rfb rfe rff rfk rfn rfo rfr rfv rkb rke rkf rkk rko rkv rna rnb rnn rno rnr rnv roa rob roe rof rok ron roo ror rov rra rrb rrf rrk rrn rrr rva rvb rve rvf rvn rvo rvr rvv v-a v-e vaa vab vae vak van vao var vav vba vbk vbo vbr vbv vea veb vee vef vek ven veo ver vfa vfb vff vfn vfr vfv vka vkb vn- vna vnf vno vnr vnv voa vob voe vof vok von voo vor vov vra vrb vre vrf vrk vrn vrr vva vvb vvo vvr vvv