a-a a-b a-t aaa aab aae aao aap aat aax ab- aba abb abe abo abp abt abx aea aeb aee aeo aep aet aex aoa aob aoe aoo aop aot aox ap- apa apb ape apo app apt apx at- ata atb ate ato atp att atx ax- axa axe axo axp axt axx b-p baa bab bae bao bap bat bax bba bbb bbe bbo bbp bbt bbx be- bea beb bee beo bep bet bex boa bob boe boo bop bot box bpa bpb bpe bpo bpp bpt bpx bta btb bte bto btp btt btx bxb bxo bxx eaa eab eae eao eap eat eax eba ebb ebe ebo ebp ebt ebx eea eeb eee eeo eep eet eex eo- eoa eob eoe eoo eop eot ep- epa epb epe epo epp ept epx eta etb ete eto etp ett etx ex- exa exe exo exp ext exx oaa oab oae oao oap oat oax ob- oba obb obe obo obp obt obx oea oeb oee oeo oep oet oex oo- ooa oob ooo oop oot oox op- opa opb ope opo opp opt opx ot- ota otb ote oto otp ott ox- oxa oxb oxo oxt oxx p-p paa pab pae pao pap pat pax pba pbb pbe pbo pbp pbt pbx pea peb pee peo pep pet pex poa pob poe poo pop pot pox ppa ppb ppe ppo ppp ppt ppx pt- pta ptb pte pto ptp ptt ptx pxe pxt t-x taa tab tae tao tap tat tax tba tbb tbe tbo tbp tbt te- tea teb tee teo tep tet tex to- toa tob toe too top tot tox tpa tpb tpe tpo tpp tpt tpx tta ttb tte tto ttp ttt ttx txe txt xaa xap xat xbe xbx xee xep xet xex xoa xoo xop xot xox xpa xpb xpe xpo xpp xpt xtp xtx xxo xxp xxx