-er a-a a-b a-t aaa aab aae aaf aan aao aar aat ab- aba abb abe abf abn abo abr abt aea aeb aee aef aen aeo aer aet af- afa afb afe aff afn afo afr aft an- ana anb ane anf ann ano anr ant aoa aob aoe aof aon aoo aor aot ar- ara arb are arf arn aro arr art at- ata atb ate atf atn ato atr att baa bab bae baf ban bao bar bat bba bbb bbe bbf bbn bbo bbr bbt be- bea beb bee bef ben beo ber bet bfa bfb bfe bff bfn bfo bfr bft bna bnb bne bnf bnn bno bnr bnt boa bob boe bof bon boo bor bot bra brb bre brf brn bro brr brt bta btb bte btf btn bto btr btt eaa eab eae eaf ean eao ear eat eba ebb ebe ebf ebn ebo ebr ebt eea eeb eee eef een eeo eer eet ef- efa efb efe eff efo efr eft en- ena enb ene enf enn eno enr ent eo- eoa eob eoe eof eon eoo eor eot era erb ere erf ern ero err ert eta etb ete etf etn eto etr ett faa fab fae faf fan fao far fat fba fbb fbe fbf fbn fbo fbr fbt fea feb fee fef fen feo fer fet ffa ffe fff ffn ffo ffr fft fna fnb fne fnf fnn fnr fnt foa fob foe fof fon foo for fot fra frb fre frf frn fro frr frt fta ftb fte ftf ftn fto ftr ftt naa nab nae naf nan nao nar nat nba nbb nbe nbf nbn nbo nbr nbt ne- nea neb nee nef nen neo ner net nfa nfb nfe nff nfn nfo nfr nft nna nnb nne nnf nnn nno nnt no- noa nob noe nof non noo nor not nra nrb nre nrf nrn nro nrr nrt nta ntb nte ntf ntn nto ntr ntt oaa oab oae oaf oan oao oar oat ob- oba obb obe obf obn obo obr obt oea oeb oee oef oen oeo oer oet of- ofa ofb ofe off ofn ofo ofr oft on- ona onb one onf onn ono onr ont oo- ooa oob oof oon ooo oor oot or- ora orb ore orf orn oro orr ort ot- ota otb ote otf otn oto otr ott ra- raa rab rae raf ran rao rar rat rba rbb rbe rbf rbn rbo rbr rbt re- rea reb ree ref ren reo rer ret rfa rfb rfe rff rfn rfo rfr rft rna rnb rnn rno rnr rnt roa rob roe rof ron roo ror rot rra rrb rrf rrn rrr rrt rta rtb rte rtf rtn rto rtr rtt taa tab tae taf tan tao tar tat tba tbb tbe tbf tbn tbo tbr tbt te- tea teb tee tef ten teo ter tet tfa tfb tfe tff tfn tfo tfr tft tna tnb tne tnf tnn tno tnr tnt to- toa tob toe tof ton too tor tot tra trb tre trf trn tro trr trt tta ttb tte ttf ttn tto ttr ttt