a-a a-b a-i aaa aab aae aai aap aas aax ab- aba abb abe abi abp abs abx aea aeb aee aei aep aes aex ai- aia aib aie aii aip ais aix ap- apa apb ape api app aps apx as- asa asb ase asi asp ass asx ax- axa axe axi axp axs axx b-p baa bab bae bai bap bas bax bba bbb bbe bbi bbp bbs bbx be- bea beb bee bei bep bes bex bi- bia bib bie bii bip bis bix bpa bpb bpe bpi bpp bps bpx bsa bsb bse bsi bsp bss bsx bxb bxi bxx eaa eab eae eai eap eas eax eba ebb ebe ebi ebp ebs ebx eea eeb eee eep ees eex eia eib eie eii eip eis eix ep- epa epb epe epi epp eps epx es- esa esb ese esi esp ess esx ex- exa exe exi exp exs exx ia- iaa iab iae iai iap ias iba ibb ibe ibi ibp ibs ibx ie- iea iee iei iep ies iex iia iib iie iii iip iis iix ipa ipb ipe ipi ipp ips ipx is- isa isb ise isi isp iss ixe ixi p-p paa pab pae pai pap pas pax pba pbb pbe pbi pbp pbs pbx pea peb pee pei pep pes pex pia pib pie pii pip pis pix ppa ppb ppe ppi ppp pps ppx ps- psa psb pse psi psp pss psx pxe pxs saa sab sae sai sap sas sax sba sbb sbe sbi sbp sbs sbx se- sea seb see sei sep ses sex sia sib sie sii sip sis six spa spb spe spi spp sps spx ss- ssa ssb sse ssi ssp sss ssx sxi sxs xaa xap xas xbe xbx xee xep xes xex xia xie xii xis xix xpa xpb xpe xpp xps xsa xsb xsi xsp xss xxi xxp xxx