-er a-a aaa aae aao aap aar aas aax aea aee aeo aep aer aes aex aoa aoe aoo aop aor aos aox ap- apa ape apo app apr aps apx ar- ara are aro arp arr ars arx as- asa ase aso asp asr ass asx ax- axa axe axo axp axr axs axx eaa eae eao eap ear eas eax eea eee eeo eep eer ees eex eo- eoa eoe eoo eop eor eos ep- epa epe epo epp epr eps epx era ere ero erp err ers es- esa ese eso esp esr ess esx ex- exa exe exo exp exr exs exx oaa oae oao oap oar oas oax oea oee oeo oep oer oes oex oo- ooa ooo oop oor oos oox op- opa ope opo opp opr ops opx or- ora ore oro orp orr ors orx os- osa ose oso osp osr oss osx ox- oxa oxo oxx p-p paa pae pao pap par pas pax pea pee peo pep per pes pex poa poe poo pop por pos pox ppa ppe ppo ppp ppr pps ppx pra pre pro prp prr prs prx ps- psa pse pso psp psr pss psx pxe pxr pxs ra- raa rae rao rap rar ras rax re- rea ree reo rep rer res rex roa roe roo rop ror ros rox rpa rpe rpo rpp rpr rps rpx rra rrp rrr rrs rsa rse rso rsp rsr rss rsx rxp rxr rxs saa sae sao sap sar sas sax se- sea see seo sep ser ses sex soa soe soo sop sor sos sox spa spe spo spp spr sps spx sr- sra sre sro srp srr srs srx ss- ssa sse sso ssp ssr sss ssx sxs xaa xap xar xas xee xep xer xes xex xoa xoo xop xor xos xox xpa xpe xpo xpp xps xrx xsa xsp xss xxo xxp xxx