-er a-a a-b aaa aab aae aaf aan aao aar aau ab- aba abb abe abf abn abo abr abu aea aeb aee aef aen aeo aer aeu af- afa afb afe aff afn afo afr afu an- ana anb ane anf ann ano anr anu aoa aob aoe aof aon aoo aor aou ar- ara arb are arf arn aro arr aru au- aua aub aue auf aun auo aur b-u baa bab bae baf ban bao bar bau bba bbb bbe bbf bbn bbo bbr bbu be- bea beb bee bef ben beo ber beu bfa bfb bfe bff bfn bfo bfr bfu bna bnb bne bnf bnn bno bnr bnu boa bob boe bof bon boo bor bou bra brb bre brf brn bro brr bru bua bub bue buf bun buo bur buu eaa eab eae eaf ean eao ear eau eba ebb ebe ebf ebn ebo ebr ebu eea eeb eee eef een eeo eer ef- efa efb efe eff efo efr en- ena enb ene enf enn eno enr enu eo- eoa eob eoe eof eon eoo eor eou era erb ere erf ern ero err eru eu- eua eub eue euf eun eur faa fab fae faf fan fao far fau fba fbb fbe fbf fbn fbo fbr fbu fea feb fee fef fen feo fer feu ffa ffe fff ffn ffo ffr ffu fna fnb fne fnf fnn fnr fnu foa fob foe fof fon foo for fou fra frb fre frf frn fro frr fru fua fub fue fuf fun fuo fur fuu naa nab nae naf nan nao nar nau nba nbb nbe nbf nbn nbo nbr nbu ne- nea neb nee nef nen neo ner neu nfa nfb nfe nff nfn nfo nfr nfu nna nnb nne nnf nnn nno nnu no- noa nob noe nof non noo nor nou nra nrb nre nrf nrn nro nrr nru nua nub nue nun nuo nur nuu oaa oab oae oaf oan oao oar oau ob- oba obb obe obf obn obo obr obu oea oeb oee oef oen oeo oer of- ofa ofb ofe off ofn ofo ofr ofu on- ona onb one onf onn ono onr onu oo- ooa oob oof oon ooo oor or- ora orb ore orf orn oro orr oru ou- oua oue ouf oun ouo our ra- raa rab rae raf ran rao rar rau rba rbb rbe rbf rbn rbo rbr rbu re- rea reb ree ref ren reo rer reu rfa rfb rfe rff rfn rfo rfr rfu rna rnb rnn rno rnr rnu roa rob roe rof ron roo ror rou rra rrb rrf rrn rrr rru rua rub rue ruf run ruo rur ruu ua- uaa uab uae uaf uan uao uar uau uba ubb ube ubf ubn ubo ubr ubu uea ueb uee uef uen uer ufa ufe uff ufn ufo ufr ufu un- una unb une unf unn uno unr unu uoa uob uoe uon uoo uor ur- ura urb ure urf urn uro urr uru uua uue uun uur uuu