-er a-a a-b a-i aaa aab aae aai aan aap aar aas ab- aba abb abe abi abn abp abr abs aea aeb aee aei aen aep aer aes ai- aia aib aie aii ain aip air ais an- ana anb ane ani ann anp anr ans ap- apa apb ape api apn app apr aps ar- ara arb are ari arn arp arr ars as- asa asb ase asi asn asp asr ass b-p baa bab bae bai ban bap bar bas bba bbb bbe bbi bbn bbp bbr bbs be- bea beb bee bei ben bep ber bes bi- bia bib bie bii bin bip bir bis bna bnb bne bni bnn bnp bnr bns bpa bpb bpe bpi bpn bpp bpr bps bra brb bre bri brn brp brr brs bsa bsb bse bsi bsn bsp bsr bss eaa eab eae eai ean eap ear eas eba ebb ebe ebi ebn ebp ebr ebs eea eeb eee een eep eer ees eia eib eie eii ein eip eir eis en- ena enb ene eni enn enp enr ens ep- epa epb epe epi epn epp epr eps era erb ere eri ern erp err ers es- esa esb ese esi esn esp esr ess ia- iaa iab iae iai ian iap iar ias iba ibb ibe ibi ibn ibp ibr ibs ie- iea iee iei ien iep ier ies iia iib iie iii iin iip iir iis in- ina inb ine ini inn inp inr ins ipa ipb ipe ipi ipn ipp ipr ips ir- ira irb ire iri irn irp irr irs is- isa isb ise isi isn isp isr iss n-i naa nab nae nai nan nap nar nas nba nbb nbe nbi nbn nbp nbr nbs ne- nea neb nee nei nen nep ner nes nia nib nie nii nin nip nir nis nna nnb nne nni nnn nnp nns npa npb npe npi npn npp npr nps nra nrb nre nri nrn nrp nrr nrs nsa nsb nse nsi nsn nsp nsr nss p-p paa pab pae pai pan pap par pas pba pbb pbe pbi pbn pbp pbr pbs pea peb pee pei pen pep per pes pia pib pie pii pin pip pir pis pn- pna pnb pne pni pnn pnp pnr pns ppa ppb ppe ppi ppn ppp ppr pps pra prb pre pri prn prp prr prs ps- psa psb pse psi psn psp psr pss ra- raa rab rae rai ran rap rar ras rba rbb rbe rbi rbn rbp rbr rbs re- rea reb ree rei ren rep rer res ria rib rie rii rin rip rir ris rna rnb rni rnn rnp rnr rns rpa rpb rpe rpi rpn rpp rpr rps rra rrb rri rrn rrp rrr rrs rsa rsb rse rsi rsn rsp rsr rss saa sab sae sai san sap sar sas sba sbb sbe sbi sbn sbp sbr sbs se- sea seb see sei sen sep ser ses sia sib sie sii sin sip sir sis sna snb sne sni snn snp snr sns spa spb spe spi spn spp spr sps sr- sra srb sre sri srn srp srr srs ss- ssa ssb sse ssi ssn ssp ssr sss