-er a-a a-b a-c a-t aaa aab aac aae aaf aan aao aar aat ab- aba abb abc abe abf abn abo abr abt ac- aca acb acc ace acf acn aco acr act aea aeb aec aee aef aen aeo aer aet af- afa afb afc afe aff afn afo afr aft an- ana anb anc ane anf ann ano anr ant aoa aob aoc aoe aof aon aoo aor aot ar- ara arb arc are arf arn aro arr art at- ata atb atc ate atf atn ato atr att baa bab bac bae baf ban bao bar bat bba bbb bbc bbe bbf bbn bbo bbr bbt bca bcb bcc bce bcf bcn bco bcr bct be- bea beb bec bee bef ben beo ber bet bfa bfb bfc bfe bff bfn bfo bfr bft bna bnb bnc bne bnf bnn bno bnr bnt boa bob boc boe bof bon boo bor bot bra brb bre brf brn bro brr brt bta btb btc bte btf btn bto btr btt c-- caa cab cac cae caf can cao car cat cba cbb cbc cbe cbf cbn cbo cbr cbt cca ccb ccc cce ccf ccn cco ccr cct ce- cea ceb cec cee cef cen ceo cer cet cfa cfb cfc cfe cff cfn cfo cfr cft cn- cna cnb cnc cne cnf cnn cno cnr cnt co- coa cob coc coe cof con coo cor cot cra crb crc cre crf crn cro crr crt cta ctb ctc cte ctf ctn cto ctr ctt eaa eab eac eae eaf ean eao ear eat eba ebb ebc ebe ebf ebn ebo ebr ebt ec- eca ecb ecc ece ecf ecn eco ecr ect eea eeb eec eee eef een eeo eer eet ef- efa efb efc efe eff efo efr eft en- ena enb enc ene enf enn eno enr ent eo- eoa eob eoc eoe eof eon eoo eor eot era erb erc ere erf ern ero err ert eta etb etc ete etf etn eto etr ett faa fab fac fae faf fan fao far fat fba fbb fbc fbe fbf fbn fbo fbr fbt fca fcb fcc fce fcf fcn fco fcr fct fea feb fec fee fef fen feo fer fet ffa ffc ffe fff ffn ffo ffr fft fna fnb fnc fne fnf fnn fnr fnt foa fob foc foe fof fon foo for fot fra frb frc fre frf frn fro frr frt fta ftb ftc fte ftf ftn fto ftr ftt naa nab nac nae naf nan nao nar nat nba nbb nbc nbe nbf nbn nbo nbr nbt nca ncb ncc nce ncf ncn nco ncr nct ne- nea neb nec nee nef nen neo ner net nfa nfb nfc nfe nff nfn nfo nfr nft nna nnb nnc nne nnf nnn nno nnt no- noa nob noc noe nof non noo nor not nra nrb nrc nre nrf nrn nro nrr nrt nta ntb ntc nte ntf ntn nto ntr ntt oaa oab oac oae oaf oan oao oar oat ob- oba obb obc obe obf obn obo obr obt oc- oca ocb occ ocf ocn oco ocr oct oea oeb oec oee oef oen oeo oer oet of- ofa ofb ofc ofe off ofn ofo ofr oft on- ona onb onc one onf onn ono onr ont oo- ooa oob ooc oof oon ooo oor oot or- ora orb orc ore orf orn oro orr ort ot- ota otb otc ote otf otn oto otr ott ra- raa rab rac rae raf ran rao rar rat rba rbb rbc rbe rbf rbn rbo rbr rbt rca rcb rcc rce rcf rcn rco rcr rct re- rea reb rec ree ref ren reo rer ret rfa rfb rfc rfe rff rfn rfo rfr rft rna rnb rnc rnn rno rnr rnt roa rob roc roe rof ron roo ror rot rra rrb rrc rrf rrn rrr rrt rta rtb rtc rte rtf rtn rto rtr rtt taa tab tac tae taf tan tao tar tat tba tbb tbc tbe tbf tbn tbo tbr tbt tca tcb tcc tce tcf tcn tco tcr tct te- tea teb tec tee tef ten teo ter tet tfa tfb tfc tfe tff tfn tfo tfr tft tna tnb tnc tne tnf tnn tno tnr tnt to- toa tob toc toe tof ton too tor tot tra trb trc tre trf trn tro trr trt tta ttb ttc tte ttf ttn tto ttr ttt