-er a-a a-b a-c aaa aab aac aae aaf aah aan aar ab- aba abb abc abe abf abh abn abr ac- aca acb acc ace acf ach acn acr aea aeb aec aee aef aeh aen aer af- afa afb afc afe aff afh afn afr aha ahb ahc ahe ahf ahh ahn ahr an- ana anb anc ane anf anh ann anr ar- ara arb arc are arf arh arn arr baa bab bac bae baf bah ban bar bba bbb bbc bbe bbf bbh bbn bbr bca bcb bcc bce bcf bch bcn bcr be- bea beb bec bee bef beh ben ber bfa bfb bfc bfe bff bfh bfn bfr bha bhb bhc bhe bhf bhh bhr bna bnb bnc bne bnf bnn bnr bra brb bre brf brh brn brr c-- caa cab cac cae caf cah can car cba cbb cbc cbe cbf cbh cbn cbr cca ccb ccc cce ccf cch ccn ccr ce- cea ceb cec cee cef ceh cen cer cfa cfb cfc cfe cff cfh cfn cfr ch- cha chb chc che chf chh chn chr cn- cna cnb cnc cne cnf cnh cnn cnr cra crb crc cre crf crh crn crr eaa eab eac eae eaf eah ean ear eba ebb ebc ebe ebf ebh ebn ebr ec- eca ecb ecc ece ecf ech ecn ecr eea eeb eec eee eef een eer ef- efa efb efc efe eff efh efr eha ehb ehc ehe ehf ehh ehn ehr en- ena enb enc ene enf enh enn enr era erb erc ere erf erh ern err faa fab fac fae faf fah fan far fba fbb fbc fbe fbf fbh fbn fbr fca fcb fcc fce fcf fcn fcr fea feb fec fee fef feh fen fer ffa ffc ffe fff ffh ffn ffr fha fhb fhc fhe fhf fhh fhn fhr fna fnb fnc fne fnf fnh fnn fnr fra frb frc fre frf frh frn frr haa hab hac hae haf hah han har hba hbb hbc hbe hbf hbh hbn hbr hca hcb hcc hce hcf hch hcn hcr he- hea heb hec hee hef heh hen her hfa hfb hfc hfe hff hfh hfn hfr hha hhb hhc hhe hhf hhh hhn hhr hna hnb hnc hne hnf hnh hnn hr- hra hrb hrc hre hrf hrh hrn hrr naa nab nac nae naf nah nan nar nba nbb nbc nbe nbf nbn nbr nca ncb ncc nce ncf nch ncn ncr ne- nea neb nec nee nef neh nen ner nfa nfb nfc nfe nff nfn nfr nha nhb nhc nhe nhf nhh nhn nhr nna nnb nnc nne nnf nnh nnn nra nrb nrc nre nrf nrn nrr ra- raa rab rac rae raf rah ran rar rba rbb rbc rbe rbf rbh rbn rbr rca rcb rcc rce rcf rch rcn rcr re- rea reb rec ree ref reh ren rer rfa rfb rfc rfe rff rfh rfn rfr rh- rha rhb rhc rhe rhf rhh rhn rhr rna rnb rnc rnh rnn rnr rra rrb rrc rrf rrh rrn rrr