-er a-a a-b a-i aaa aab aae aaf aai aan aar aas ab- aba abb abe abf abi abn abr abs aea aeb aee aef aei aen aer aes af- afa afb afe aff afi afn afr afs ai- aia aib aie aif aii ain air ais an- ana anb ane anf ani ann anr ans ar- ara arb are arf ari arn arr ars as- asa asb ase asf asi asn asr ass baa bab bae baf bai ban bar bas bba bbb bbe bbf bbi bbn bbr bbs be- bea beb bee bef bei ben ber bes bfa bfb bfe bff bfi bfn bfr bfs bi- bia bib bie bif bii bin bir bis bna bnb bne bnf bni bnn bnr bns bra brb bre brf bri brn brr brs bsa bsb bse bsf bsi bsn bsr bss eaa eab eae eaf eai ean ear eas eba ebb ebe ebf ebi ebn ebr ebs eea eeb eee eef een eer ees ef- efa efb efe eff efi efr efs eia eib eie eif eii ein eir eis en- ena enb ene enf eni enn enr ens era erb ere erf eri ern err ers es- esa esb ese esf esi esn esr ess faa fab fae faf fai fan far fas fba fbb fbe fbf fbi fbn fbr fbs fea feb fee fef fei fen fer fes ffa ffe fff ffi ffn ffr ffs fia fib fie fif fii fin fir fis fna fnb fne fnf fni fnn fnr fns fra frb fre frf fri frn frr frs fsa fsb fse fsf fsi fsn fsr fss i-f ia- iaa iab iae iaf iai ian iar ias iba ibb ibe ibf ibi ibn ibr ibs ie- iea iee ief iei ien ier ies ifa ifb ife iff ifi ifn ifr ifs iia iib iie iif iii iin iir iis in- ina inb ine inf ini inn inr ins ir- ira irb ire irf iri irn irr irs is- isa isb ise isf isi isn isr iss n-i naa nab nae naf nai nan nar nas nba nbb nbe nbf nbi nbn nbr nbs ne- nea neb nee nef nei nen ner nes nfa nfb nfe nff nfi nfn nfr nfs nia nib nie nif nii nin nir nis nna nnb nne nnf nni nnn nns nra nrb nre nrf nri nrn nrr nrs nsa nsb nse nsf nsi nsn nsr nss ra- raa rab rae raf rai ran rar ras rba rbb rbe rbf rbi rbn rbr rbs re- rea reb ree ref rei ren rer res rfa rfb rfe rff rfi rfn rfr rfs ria rib rie rif rii rin rir ris rna rnb rni rnn rnr rns rra rrb rrf rri rrn rrr rrs rsa rsb rse rsf rsi rsn rsr rss saa sab sae saf sai san sar sas sba sbb sbe sbf sbi sbn sbr sbs se- sea seb see sef sei sen ser ses sfa sfb sfe sff sfi sfn sfr sfs sia sib sie sif sii sin sir sis sna snb sne snf sni snn snr sns sr- sra srb sre srf sri srn srr srs ss- ssa ssb sse ssf ssi ssn ssr sss