-er b-p bbb bbe bbn bbo bbp bbr bbs bbt bbx be- beb bee ben beo bep ber bes bet bex bnb bne bnn bno bnp bnr bns bnt bnx bob boe bon boo bop bor bos bot box bpb bpe bpn bpo bpp bpr bps bpt bpx brb bre brn bro brp brr brs brt brx bsb bse bsn bso bsp bsr bss bst bsx btb bte btn bto btp btr bts btt btx bxb bxn bxo bxx ebb ebe ebn ebo ebp ebr ebs ebt ebx eeb eee een eeo eep eer ees eet eex en- enb ene enn eno enp enr ens ent eo- eob eoe eon eoo eop eor eos eot ep- epb epe epn epo epp epr eps ept epx erb ere ern ero erp err ers ert es- esb ese esn eso esp esr ess est esx etb ete etn eto etp etr ets ett etx ex- exe exo exp exr exs ext exx nbb nbe nbn nbo nbp nbr nbs nbt nbx ne- neb nee nen neo nep ner nes net nex nnb nne nnn nno nnp nns nnt no- nob noe non noo nop nor nos not nox npb npe npn npo npp npr nps npt nrb nre nrn nro nrp nrr nrs nrt nrx nsb nse nsn nso nsp nsr nss nst nsx ntb nte ntn nto ntp ntr nts ntt ntx nxt ob- obb obe obn obo obp obr obs obt obx oeb oee oen oeo oep oer oes oet oex on- onb one onn ono onp onr ons ont onx oo- oob oon ooo oop oor oos oot oox op- opb ope opn opo opp opr ops opt opx or- orb ore orn oro orp orr ors ort orx os- osb ose osn oso osp osr oss ost osx ot- otb ote otn oto otp otr ots ott ox- oxb oxn oxo oxt oxx p-p pbb pbe pbn pbo pbp pbr pbs pbt pbx peb pee pen peo pep per pes pet pex pn- pnb pne pnn pno pnp pnr pns pnt pnx pob poe pon poo pop por pos pot pox ppb ppe ppn ppo ppp ppr pps ppt ppx prb pre prn pro prp prr prs prt prx ps- psb pse psn pso psp psr pss pst psx pt- ptb pte ptn pto ptp ptr pts ptt ptx pxe pxr pxs pxt rbb rbe rbn rbo rbp rbr rbs rbt rbx re- reb ree ren reo rep rer res ret rex rnb rnn rno rnp rnr rns rnt rob roe ron roo rop ror ros rot rox rpb rpe rpn rpo rpp rpr rps rpt rpx rrb rrn rrp rrr rrs rrt rsb rse rsn rso rsp rsr rss rst rsx rtb rte rtn rto rtp rtr rts rtt rtx rxp rxr rxs sbb sbe sbn sbo sbp sbr sbs sbt sbx se- seb see sen seo sep ser ses set sex snb sne snn sno snp snr sns snt sob soe son soo sop sor sos sot sox spb spe spn spo spp spr sps spt spx sr- srb sre srn sro srp srr srs srt srx ss- ssb sse ssn sso ssp ssr sss sst ssx stb ste stn sto stp str sts stt stx sxn sxs sxt t-x tbb tbe tbn tbo tbp tbr tbs tbt te- teb tee ten teo tep ter tes tet tex tnb tne tnn tno tnp tnr tns tnt tnx to- tob toe ton too top tor tos tot tox tpb tpe tpn tpo tpp tpr tps tpt tpx trb tre trn tro trp trr trs trt trx tsb tse tsn tso tsp tsr tss tst tsx ttb tte ttn tto ttp ttr tts ttt ttx txe txn txs txt xbe xbr xbx xee xen xep xer xes xet xex xno xns xon xoo xop xor xos xot xox xpb xpe xpn xpo xpp xps xpt xrt xrx xsb xsp xss xst xtp xtr xts xtx xxo xxp xxx