-er a-a a-b a-c aaa aab aac aad aae aaf aan aar aas ab- aba abb abc abd abe abf abn abr abs ac- aca acb acc acd ace acf acn acr acs ad- ada adb adc add ade adf adn adr ads aea aeb aec aed aee aef aen aer aes af- afa afb afc afd afe aff afn afr afs an- ana anb anc and ane anf ann anr ans ar- ara arb arc ard are arf arn arr ars as- asa asb asc asd ase asf asn asr ass baa bab bac bad bae baf ban bar bas bba bbb bbc bbd bbe bbf bbn bbr bbs bca bcb bcc bcd bce bcf bcn bcr bcs bda bdb bdc bdd bde bdf bdr bds be- bea beb bec bed bee bef ben ber bes bfa bfb bfc bfd bfe bff bfn bfr bfs bna bnb bnc bnd bne bnf bnn bnr bns bra brb brd bre brf brn brr brs bsa bsb bsc bsd bse bsf bsn bsr bss c-- caa cab cac cad cae caf can car cas cba cbb cbc cbd cbe cbf cbn cbr cbs cca ccb ccc ccd cce ccf ccn ccr ccs cda cdb cdc cdd cde cdf cdn cdr cds ce- cea ceb cec ced cee cef cen cer ces cfa cfb cfc cfd cfe cff cfn cfr cfs cn- cna cnb cnc cnd cne cnf cnn cnr cns cra crb crc crd cre crf crn crr crs csa csb csc csd cse csf csn csr css daa dab dac dad dae daf dan dar das dba dbb dbc dbd dbe dbf dbn dbr dbs dca dcb dcc dcd dce dcf dcn dcr dcs dda ddb ddc ddd dde ddf ddn ddr dds de- dea deb dec ded dee def den der des dfa dfb dfc dfd dfe dff dfn dfr dfs dna dnb dnc dnd dne dnf dnn dnr dns dra drb drc drd dre drn drr drs dsa dsb dsc dsd dse dsf dsn dsr dss eaa eab eac ead eae eaf ean ear eas eba ebb ebc ebd ebe ebf ebn ebr ebs ec- eca ecb ecc ecd ece ecf ecn ecr ecs ed- eda edb edc edd ede edf edn edr eds eea eeb eec eed eee eef een eer ees ef- efa efb efc efd efe eff efr efs en- ena enb enc end ene enf enn enr ens era erb erc erd ere erf ern err ers es- esa esb esc esd ese esf esn esr ess faa fab fac fad fae faf fan far fas fba fbb fbc fbd fbe fbf fbn fbr fbs fca fcb fcc fcd fce fcf fcn fcr fcs fda fdb fdc fdd fde fdf fdn fdr fds fea feb fec fed fee fef fen fer fes ffa ffc ffd ffe fff ffn ffr ffs fna fnb fnc fnd fne fnf fnn fnr fns fra frb frc frd fre frf frn frr frs fsa fsb fsc fsd fse fsf fsn fsr fss naa nab nac nad nae naf nan nar nas nba nbb nbc nbd nbe nbf nbn nbr nbs nca ncb ncc ncd nce ncf ncn ncr ncs nda ndb ndc ndd nde ndf ndn ndr nds ne- nea neb nec ned nee nef nen ner nes nfa nfb nfc nfd nfe nff nfn nfr nfs nna nnb nnc nne nnf nnn nns nra nrb nrc nrd nre nrf nrn nrr nrs nsa nsb nsc nsd nse nsf nsn nsr nss ra- raa rab rac rad rae raf ran rar ras rba rbb rbc rbd rbe rbf rbn rbr rbs rca rcb rcc rcd rce rcf rcn rcr rcs rda rdb rdc rdd rde rdf rdn rdr rds re- rea reb rec red ree ref ren rer res rfa rfb rfc rfd rfe rff rfn rfr rfs rna rnb rnc rnd rnn rnr rns rra rrb rrc rrd rrf rrn rrr rrs rsa rsb rsc rsd rse rsf rsn rsr rss saa sab sac sad sae saf san sar sas sba sbb sbc sbd sbe sbf sbn sbr sbs sca scb scc scd sce scf scn scr scs sda sdb sdc sdd sde sdf sdn sdr sds se- sea seb sec sed see sef sen ser ses sfa sfb sfc sfd sfe sff sfn sfr sfs sna snb snc snd sne snf snn snr sns sr- sra srb src srd sre srf srn srr srs ss- ssa ssb ssc ssd sse ssf ssn ssr sss