-er a-a a-b a-i a-t aaa aab aae aai aao aap aar aat aax ab- aba abb abe abi abo abp abr abt abx aea aeb aee aei aeo aep aer aet aex ai- aia aib aie aii aio aip air ait aix aoa aob aoe aoi aoo aop aor aot aox ap- apa apb ape api apo app apr apt apx ar- ara arb are ari aro arp arr art arx at- ata atb ate ati ato atp atr att atx ax- axa axe axi axo axp axr axt axx b-p baa bab bae bai bao bap bar bat bax bba bbb bbe bbi bbo bbp bbr bbt bbx be- bea beb bee bei beo bep ber bet bex bi- bia bib bie bii bio bip bir bit bix boa bob boe boi boo bop bor bot box bpa bpb bpe bpi bpo bpp bpr bpt bpx bra brb bre bri bro brp brr brt brx bta btb bte bti bto btp btr btt btx bxb bxi bxo bxx eaa eab eae eai eao eap ear eat eax eba ebb ebe ebi ebo ebp ebr ebt ebx eea eeb eee eeo eep eer eet eex eia eib eie eii eio eip eir eit eix eo- eoa eob eoe eoi eoo eop eor eot ep- epa epb epe epi epo epp epr ept epx era erb ere eri ero erp err ert eta etb ete eti eto etp etr ett etx ex- exa exe exi exo exp exr ext exx ia- iaa iab iae iai iao iap iar iat iba ibb ibe ibi ibo ibp ibr ibt ibx ie- iea iee iei iep ier iet iex iia iib iie iii iio iip iir iit iix io- ioa iob ioe ioi ioo iop ior iot ipa ipb ipe ipi ipo ipp ipr ipt ipx ir- ira irb ire iri iro irp irr irt irx ita itb ite iti ito itp itt itx ixe ixi o-i oaa oab oae oai oao oap oar oat oax ob- oba obb obe obi obo obp obr obt obx oea oeb oee oei oeo oep oer oet oex oia oib oie oii oio oip oir oit oo- ooa oob ooi ooo oop oor oot oox op- opa opb ope opi opo opp opr opt opx or- ora orb ore ori oro orp orr ort orx ot- ota otb ote oti oto otp otr ott ox- oxa oxb oxi oxo oxt oxx p-p paa pab pae pai pao pap par pat pax pba pbb pbe pbi pbo pbp pbr pbt pbx pea peb pee pei peo pep per pet pex pia pib pie pii pio pip pir pit pix poa pob poe poi poo pop por pot pox ppa ppb ppe ppi ppo ppp ppr ppt ppx pra prb pre pri pro prp prr prt prx pt- pta ptb pte pti pto ptp ptr ptt ptx pxe pxr pxt ra- raa rab rae rai rao rap rar rat rax rba rbb rbe rbi rbo rbp rbr rbt rbx re- rea reb ree rei reo rep rer ret rex ria rib rie rii rio rip rir rit rix roa rob roe roi roo rop ror rot rox rpa rpb rpe rpi rpo rpp rpr rpt rpx rra rrb rri rrp rrr rrt rta rtb rte rti rto rtp rtr rtt rtx rxp rxr t-x taa tab tae tai tao tap tar tat tax tba tbb tbe tbi tbo tbp tbr tbt te- tea teb tee tei teo tep ter tet tex tia tib tie tii tio tip tir tit tix to- toa tob toe toi too top tor tot tox tpa tpb tpe tpi tpo tpp tpr tpt tpx tra trb tre tri tro trp trr trt trx tta ttb tte tti tto ttp ttr ttt ttx txe txi txt xaa xap xar xat xbe xbr xbx xee xep xer xet xex xia xie xii xio xit xix xoa xoi xoo xop xor xot xox xpa xpb xpe xpo xpp xpt xrt xrx xti xtp xtr xtx xxi xxo xxp xxx