a-a aaa aae aap aas aax aea aee aep aes aex ap- apa ape app aps apx as- asa ase asp ass asx ax- axa axe axp axs axx eaa eae eap eas eax eea eee eep ees eex ep- epa epe epp eps epx es- esa ese esp ess esx ex- exa exe exp exs exx p-p paa pae pap pas pax pea pee pep pes pex ppa ppe ppp pps ppx ps- psa pse psp pss psx pxe pxs saa sae sap sas sax se- sea see sep ses sex spa spe spp sps spx ss- ssa sse ssp sss ssx sxs xaa xap xas xee xep xes xex xpa xpe xpp xps xsa xsp xss xxp xxx