-er a-a a-b a-i aaa aab aae aai aan aao aap aar aas ab- aba abb abe abi abn abo abp abr abs aea aeb aee aei aen aeo aep aer aes ai- aia aib aie aii ain aio aip air ais an- ana anb ane ani ann ano anp anr ans aoa aob aoe aoi aon aoo aop aor aos ap- apa apb ape api apn apo app apr aps ar- ara arb are ari arn aro arp arr ars as- asa asb ase asi asn aso asp asr ass b-p baa bab bae bai ban bao bap bar bas bba bbb bbe bbi bbn bbo bbp bbr bbs be- bea beb bee bei ben beo bep ber bes bi- bia bib bie bii bin bio bip bir bis bna bnb bne bni bnn bno bnp bnr bns boa bob boe boi bon boo bop bor bos bpa bpb bpe bpi bpn bpo bpp bpr bps bra brb bre bri brn bro brp brr brs bsa bsb bse bsi bsn bso bsp bsr bss eaa eab eae eai ean eao eap ear eas eba ebb ebe ebi ebn ebo ebp ebr ebs eea eeb eee een eeo eep eer ees eia eib eie eii ein eio eip eir eis en- ena enb ene eni enn eno enp enr ens eo- eoa eob eoe eoi eon eoo eop eor eos ep- epa epb epe epi epn epo epp epr eps era erb ere eri ern ero erp err ers es- esa esb ese esi esn eso esp esr ess ia- iaa iab iae iai ian iao iap iar ias iba ibb ibe ibi ibn ibo ibp ibr ibs ie- iea iee iei ien iep ier ies iia iib iie iii iin iio iip iir iis in- ina inb ine ini inn ino inp inr ins io- ioa iob ioe ioi ion ioo iop ior ios ipa ipb ipe ipi ipn ipo ipp ipr ips ir- ira irb ire iri irn iro irp irr irs is- isa isb ise isi isn iso isp isr iss n-i naa nab nae nai nan nao nap nar nas nba nbb nbe nbi nbn nbo nbp nbr nbs ne- nea neb nee nei nen neo nep ner nes nia nib nie nii nin nio nip nir nis nna nnb nne nni nnn nno nnp nns no- noa nob noe noi non noo nop nor nos npa npb npe npi npn npo npp npr nps nra nrb nre nri nrn nro nrp nrr nrs nsa nsb nse nsi nsn nso nsp nsr nss o-i oaa oab oae oai oan oao oap oar oas ob- oba obb obe obi obn obo obp obr obs oea oeb oee oei oen oeo oep oer oes oia oib oie oii oin oio oip oir ois on- ona onb one oni onn ono onp onr ons oo- ooa oob ooi oon ooo oop oor oos op- opa opb ope opi opn opo opp opr ops or- ora orb ore ori orn oro orp orr ors os- osa osb ose osi osn oso osp osr oss p-p paa pab pae pai pan pao pap par pas pba pbb pbe pbi pbn pbo pbp pbr pbs pea peb pee pei pen peo pep per pes pia pib pie pii pin pio pip pir pis pn- pna pnb pne pni pnn pno pnp pnr pns poa pob poe poi pon poo pop por pos ppa ppb ppe ppi ppn ppo ppp ppr pps pra prb pre pri prn pro prp prr prs ps- psa psb pse psi psn pso psp psr pss ra- raa rab rae rai ran rao rap rar ras rba rbb rbe rbi rbn rbo rbp rbr rbs re- rea reb ree rei ren reo rep rer res ria rib rie rii rin rio rip rir ris rna rnb rni rnn rno rnp rnr rns roa rob roe roi ron roo rop ror ros rpa rpb rpe rpi rpn rpo rpp rpr rps rra rrb rri rrn rrp rrr rrs rsa rsb rse rsi rsn rso rsp rsr rss saa sab sae sai san sao sap sar sas sba sbb sbe sbi sbn sbo sbp sbr sbs se- sea seb see sei sen seo sep ser ses sia sib sie sii sin sio sip sir sis sna snb sne sni snn sno snp snr sns soa sob soe soi son soo sop sor sos spa spb spe spi spn spo spp spr sps sr- sra srb sre sri srn sro srp srr srs ss- ssa ssb sse ssi ssn sso ssp ssr sss