-er a-a a-b a-i aaa aab aae aai aak aan aao aap aar aas ab- aba abb abe abi abk abn abo abp abr abs aea aeb aee aei aek aen aeo aep aer aes ai- aia aib aie aii aik ain aio aip air ais aka akb ake aki akk akn ako akp akr aks an- ana anb ane ani ank ann ano anp anr ans aoa aob aoe aoi aok aon aoo aop aor aos ap- apa apb ape api apk apn apo app apr aps ar- ara arb are ari ark arn aro arp arr ars as- asa asb ase asi ask asn aso asp asr ass b-p baa bab bae bai bak ban bao bap bar bas bba bbb bbe bbi bbk bbn bbo bbp bbr bbs be- bea beb bee bei bek ben beo bep ber bes bi- bia bib bie bii bik bin bio bip bir bis bka bkb bke bkk bkn bko bkp bkr bks bna bnb bne bni bnk bnn bno bnp bnr bns boa bob boe boi bok bon boo bop bor bos bpa bpb bpe bpi bpn bpo bpp bpr bps bra brb bre bri brk brn bro brp brr brs bsa bsb bse bsi bsk bsn bso bsp bsr bss eaa eab eae eai eak ean eao eap ear eas eba ebb ebe ebi ebk ebn ebo ebp ebr ebs eea eeb eee eek een eeo eep eer ees eia eib eie eii eik ein eio eip eir eis eka ekb eke eki eko ekp ekr eks en- ena enb ene eni enk enn eno enp enr ens eo- eoa eob eoe eoi eok eon eoo eop eor eos ep- epa epb epe epi epn epo epp epr eps era erb ere eri erk ern ero erp err ers es- esa esb ese esi esk esn eso esp esr ess ia- iaa iab iae iai ian iao iap iar ias iba ibb ibe ibi ibk ibn ibo ibp ibr ibs ie- iea iee iei iek ien iep ier ies iia iib iie iii iin iio iip iir iis ika ikb ike iki ikk iko ikr iks in- ina inb ine ini ink 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 irk irn iro irp irr irs is- isa isb ise isi isk isn iso isp isr iss ka- kaa kab kae kai kak kan kao kap kar kas kba kbb kbe kbi kbk kbn kbo kbp kbr kbs ke- kea keb kee kei kek ken keo kep ker kes kia kib kie kii kik kin kio kip kir kis kkb kke kki kkk kkn kkp kkr kks kn- kna kne kni knk knn kno knp knr koa kob koe koi kok kon koo kop kor kos kpa kpe kpi kpk kpn kpo kpp kpr kps kra kri krk krn kro krp krr krs ksa ksb kse ksi ksk ksn kso ksp ksr kss n-i naa nab nae nai nak nan nao nap nar nas nba nbb nbe nbi nbk nbn nbo nbp nbr nbs ne- nea neb nee nei nek nen neo nep ner nes nia nib nie nii nik nin nio nip nir nis nka nke nki nkk nkn nko nkp nkr nks nna nnb nne nni nnk nnn nno nnp nns no- noa nob noe noi nok non noo nop nor nos npa npb npe npi npn npo npp npr nps nra nrb nre nri nrk nrn nro nrp nrr nrs nsa nsb nse nsi nsk nsn nso nsp nsr nss o-i oaa oab oae oai oak oan oao oap oar oas ob- oba obb obe obi obk obn obo obp obr obs oea oeb oee oei oen oeo oep oer oes oia oib oie oii oik oin oio oip oir ois oka okb oke oki okk oko okp okr oks on- ona onb one oni onk onn ono onp onr ons oo- ooa oob ooi ook oon ooo oop oor oos op- opa opb ope opi opk opn opo opp opr ops or- ora orb ore ori ork orn oro orp orr ors os- osa osb ose osi osk osn oso osp osr oss p-p paa pab pae pai pak pan pao pap par pas pba pbb pbe pbi pbk pbn pbo pbp pbr pbs pea peb pee pei pek pen peo pep per pes pia pib pie pii pik pin pio pip pir pis pka pkb pke pki pkn pko pkp pkr pks pn- pna pnb pne pni pnk pnn pno pnp pnr pns poa pob poe poi pok pon poo pop por pos ppa ppb ppe ppi ppk ppn ppo ppp ppr pps pra prb pre pri prk prn pro prp prr prs ps- psa psb pse psi psk psn pso psp psr pss ra- raa rab rae rai rak ran rao rap rar ras rba rbb rbe rbi rbk rbn rbo rbp rbr rbs re- rea reb ree rei rek ren reo rep rer res ria rib rie rii rik rin rio rip rir ris rkb rke rkk rko rkp rks rna rnb rni rnn rno rnp rnr rns roa rob roe roi rok ron roo rop ror ros rpa rpb rpe rpi rpk rpn rpo rpp rpr rps rra rrb rri rrk rrn rrp rrr rrs rsa rsb rse rsi rsk rsn rso rsp rsr rss saa sab sae sai sak san sao sap sar sas sba sbb sbe sbi sbk sbn sbo sbp sbr sbs se- sea seb see sei sek sen seo sep ser ses sia sib sie sii sik sin sio sip sir sis sk- ska skb ske ski skk sko skp skr sks sna snb sne sni snk snn sno snp snr sns soa sob soe soi sok son soo sop sor sos spa spb spe spi spk spn spo spp spr sps sr- sra srb sre sri srk srn sro srp srr srs ss- ssa ssb