-er a-a a-i aaa aae aai aan aap aar aax aea aee aei aen aep aer aex ai- aia aie aii ain aip air aix an- ana ane ani ann anp anr anx ap- apa ape api apn app apr apx ar- ara are ari arn arp arr arx ax- axa axe axi axn axp axr axx eaa eae eai ean eap ear eax eea eee een eep eer eex eia eie eii ein eip eir eix en- ena ene eni enn enp enr ep- epa epe epi epn epp epr epx era ere eri ern erp err ex- exa exe exi exp exr exx ia- iaa iae iai ian iap iar ie- iea iee iei ien iep ier iex iia iie iii iin iip iir iix in- ina ine ini inn inp inr inx ipa ipe ipi ipn ipp ipr ipx ir- ira ire iri irn irp irr irx ixe ixi ixn n-i naa nae nai nan nap nar nax ne- nea nee nei nen nep ner nex nia nie nii nin nip nir nix nna nne nni nnn nnp npa npe npi npn npp npr nra nre nri nrn nrp nrr nrx p-p paa pae pai pan pap par pax pea pee pei pen pep per pex pia pie pii pin pip pir pix pn- pna pne pni pnn pnp pnr pnx ppa ppe ppi ppn ppp ppr ppx pra pre pri prn prp prr prx pxe pxr ra- raa rae rai ran rap rar rax re- rea ree rei ren rep rer rex ria rie rii rin rip rir rix rna rni rnn rnp rnr rpa rpe rpi rpn rpp rpr rpx rra rri rrn rrp rrr rxp rxr xaa xan xap xar xee xen xep xer xex xia xie xii xin xix xna xpa xpe xpn xpp xrx xxi xxp xxx