-er a-a a-b a-i a-t aaa aab aae aai aap aar aat aax ab- aba abb abe abi abp abr abt abx aea aeb aee aei aep aer aet aex ai- aia aib aie aii aip air ait aix ap- apa apb ape api app apr apt apx ar- ara arb are ari arp arr art arx at- ata atb ate ati atp atr att atx ax- axa axe axi axp axr axt axx b-p baa bab bae bai bap bar bat bax bba bbb bbe bbi bbp bbr bbt bbx be- bea beb bee bei bep ber bet bex bi- bia bib bie bii bip bir bit bix bpa bpb bpe bpi bpp bpr bpt bpx bra brb bre bri brp brr brt brx bta btb bte bti btp btr btt btx bxb bxi bxx eaa eab eae eai eap ear eat eax eba ebb ebe ebi ebp ebr ebt ebx eea eeb eee eep eer eet eex eia eib eie eii eip eir eit eix ep- epa epb epe epi epp epr ept epx era erb ere eri erp err ert eta etb ete eti etp etr ett etx ex- exa exe exi exp exr ext exx ia- iaa iab iae iai iap iar iat iba ibb ibe ibi ibp ibr ibt ibx ie- iea iee iei iep ier iet iex iia iib iie iii iip iir iit iix ipa ipb ipe ipi ipp ipr ipt ipx ir- ira irb ire iri irp irr irt irx ita itb ite iti itp itt itx ixe ixi p-p paa pab pae pai pap par pat pax pba pbb pbe pbi pbp pbr pbt pbx pea peb pee pei pep per pet pex pia pib pie pii pip pir pit pix ppa ppb ppe ppi ppp ppr ppt ppx pra prb pre pri prp prr prt prx pt- pta ptb pte pti ptp ptr ptt ptx pxe pxr pxt ra- raa rab rae rai rap rar rat rax rba rbb rbe rbi rbp rbr rbt rbx re- rea reb ree rei rep rer ret rex ria rib rie rii rip rir rit rix rpa rpb rpe rpi rpp rpr rpt rpx rra rrb rri rrp rrr rrt rta rtb rte rti rtp rtr rtt rtx rxp rxr t-x taa tab tae tai tap tar tat tax tba tbb tbe tbi tbp tbr tbt te- tea teb tee tei tep ter tet tex tia tib tie tii tip tir tit tix tpa tpb tpe tpi tpp tpr tpt tpx tra trb tre tri trp trr trt trx tta ttb tte tti ttp ttr ttt ttx txe txi txt xaa xap xar xat xbe xbr xbx xee xep xer xet xex xia xie xii xit xix xpa xpb xpe xpp xpt xrt xrx xti xtp xtr xtx xxi xxp xxx