a-a a-b a-i a-t aaa aab aai aao aap aar aat aax ab- aba abb abi abo abp abr abt abx ai- aia aib aii aio aip air ait aix aoa aob aoi aoo aop aor aot aox ap- apa apb api apo app apr apt apx ar- ara arb ari aro arp arr art arx at- ata atb ati ato atp atr att atx ax- axa axi axo axp axr axt axx b-p baa bab bai bao bap bar bat bax bba bbb bbi bbo bbp bbr bbt bbx bi- bia bib bii bio bip bir bit bix boa bob boi boo bop bor bot box bpa bpb bpi bpo bpp bpr bpt bpx bra brb bri bro brp brr brt brx bta btb bti bto btp btr btt btx bxb bxi bxo bxx ia- iaa iab iai iao iap iar iat iba ibb ibi ibo ibp ibr ibt ibx iia iib iii iio iip iir iit iix io- ioa iob ioi ioo iop ior iot ipa ipb ipi ipo ipp ipr ipt ipx ir- ira irb iri iro irp irr irt irx ita itb iti ito itp itt itx ixi o-i oaa oab oai oao oap oar oat oax ob- oba obb obi obo obp obr obt obx oia oib oii oio oip oir oit oo- ooa oob ooi ooo oop oor oot oox op- opa opb opi opo opp opr opt opx or- ora orb ori oro orp orr ort orx ot- ota otb oti oto otp otr ott ox- oxa oxb oxi oxo oxt oxx p-p paa pab pai pao pap par pat pax pba pbb pbi pbo pbp pbr pbt pbx pia pib pii pio pip pir pit pix poa pob poi poo pop por pot pox ppa ppb ppi ppo ppp ppr ppt ppx pra prb pri pro prp prr prt prx pt- pta ptb pti pto ptp ptr ptt ptx pxr pxt ra- raa rab rai rao rap rar rat rax rba rbb rbi rbo rbp rbr rbt rbx ria rib rii rio rip rir rit rix roa rob roi roo rop ror rot rox rpa rpb rpi rpo rpp rpr rpt rpx rra rrb rri rrp rrr rrt rta rtb rti rto rtp rtr rtt rtx rxp rxr t-x taa tab tai tao tap tar tat tax tba tbb tbi tbo tbp tbr tbt tia tib tii tio tip tir tit tix to- toa tob toi too top tor tot tox tpa tpb tpi tpo tpp tpr tpt tpx tra trb tri tro trp trr trt trx tta ttb tti tto ttp ttr ttt ttx txi txt xaa xap xar xat xbr xbx xia xii xio xit xix xoa xoi xoo xop xor xot xox xpa xpb xpo xpp xpt xrt xrx xti xtp xtr xtx xxi xxo xxp xxx