-er a-a a-b a-t aaa aab aae aaf aak aan aao aar aat ab- aba abb abe abf abk abn abo abr abt aea aeb aee aef aek aen aeo aer aet af- afa afb afe aff afk afn afo afr aft aka akb ake akk akn ako akr an- ana anb ane anf ank ann ano anr ant aoa aob aoe aof aok aon aoo aor aot ar- ara arb are arf ark arn aro arr art at- ata atb ate atf atn ato atr att baa bab bae baf bak ban bao bar bat bba bbb bbe bbf bbk bbn bbo bbr bbt be- bea beb bee bef bek ben beo ber bet bfa bfb bfe bff bfn bfo bfr bft bka bkb bke bkf bkk bkn bko bkr bkt bna bnb bne bnf bnk bnn bno bnr bnt boa bob boe bof bok bon boo bor bot bra brb bre brf brk brn bro brr brt bta btb bte btf btk btn bto btr btt eaa eab eae eaf eak ean eao ear eat eba ebb ebe ebf ebk ebn ebo ebr ebt eea eeb eee eef eek een eeo eer eet ef- efa efb efe eff efo efr eft eka ekb eke ekf eko ekr ekt en- ena enb ene enf enk enn eno enr ent eo- eoa eob eoe eof eok eon eoo eor eot era erb ere erf erk ern ero err ert eta etb ete etf etk etn eto etr ett faa fab fae faf fak fan fao far fat fba fbb fbe fbf fbk fbn fbo fbr fbt fea feb fee fef fek fen feo fer fet ffa ffe fff ffk ffn ffo ffr fft fka fkb fkf fkk fkt fna fnb fne fnf fnk fnn fnr fnt foa fob foe fof fok fon foo for fot fra frb fre frf frk frn fro frr frt fta ftb fte ftf ftk ftn fto ftr ftt k-t ka- kaa kab kae kaf kak kan kao kar kat kba kbb kbe kbf kbk kbn kbo kbr ke- kea keb kee kef kek ken keo ker ket kfa kff kfo kkb kke kkk kkn kkr kkt kn- kna kne knf knk knn kno knr knt koa kob koe kof kok kon koo kor kot kra krf krk krn kro krr krt kta ktb kte ktf ktk ktn kto ktr ktt naa nab nae naf nak nan nao nar nat nba nbb nbe nbf nbk nbn nbo nbr nbt ne- nea neb nee nef nek nen neo ner net nfa nfb nfe nff nfk nfn nfo nfr nft nka nke nkf nkk nkn nko nkr nkt nna nnb nne nnf nnk nnn nno nnt no- noa nob noe nof nok non noo nor not nra nrb nre nrf nrk nrn nro nrr nrt nta ntb nte ntf ntk ntn nto ntr ntt oaa oab oae oaf oak oan oao oar oat ob- oba obb obe obf obk obn obo obr obt oea oeb oee oef oen oeo oer oet of- ofa ofb ofe off ofn ofo ofr oft oka okb oke okk oko okr on- ona onb one onf onk onn ono onr ont oo- ooa oob oof ook oon ooo oor oot or- ora orb ore orf ork orn oro orr ort ot- ota otb ote otf otk otn oto otr ott ra- raa rab rae raf rak ran rao rar rat rba rbb rbe rbf rbk rbn rbo rbr rbt re- rea reb ree ref rek ren reo rer ret rfa rfb rfe rff rfk rfn rfo rfr rft rkb rke rkf rkk rko rkt rna rnb rnn rno rnr rnt roa rob roe rof rok ron roo ror rot rra rrb rrf rrk rrn rrr rrt rta rtb rte rtf rtk rtn rto rtr rtt taa tab tae taf tak tan tao tar tat tba tbb tbe tbf tbk tbn tbo tbr tbt te- tea teb tee tef tek ten teo ter tet tfa tfb tfe tff tfk tfn tfo tfr tft tka tkb tke tkk tko tkr tkt tna tnb tne tnf tnk tnn tno tnr tnt to- toa tob toe tof tok ton too tor tot tra trb tre trf trk trn tro trr trt tta ttb tte ttf ttk ttn tto ttr ttt