-er b-p bbb bbe bbn bbo bbp bbr bbs bbt be- beb bee ben beo bep ber bes bet bnb bne bnn bno bnp bnr bns bnt bob boe bon boo bop bor bos bot bpb bpe bpn bpo bpp bpr bps bpt brb bre brn bro brp brr brs brt bsb bse bsn bso bsp bsr bss bst btb bte btn bto btp btr bts btt ebb ebe ebn ebo ebp ebr ebs ebt eeb eee een eeo eep eer ees eet 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 erb ere ern ero erp err ers ert es- esb ese esn eso esp esr ess est etb ete etn eto etp etr ets ett nbb nbe nbn nbo nbp nbr nbs nbt ne- neb nee nen neo nep ner nes net nnb nne nnn nno nnp nns nnt no- nob noe non noo nop nor nos not npb npe npn npo npp npr nps npt nrb nre nrn nro nrp nrr nrs nrt nsb nse nsn nso nsp nsr nss nst ntb nte ntn nto ntp ntr nts ntt ob- obb obe obn obo obp obr obs obt oeb oee oen oeo oep oer oes oet on- onb one onn ono onp onr ons ont oo- oob oon ooo oop oor oos oot op- opb ope opn opo opp opr ops opt or- orb ore orn oro orp orr ors ort os- osb ose osn oso osp osr oss ost ot- otb ote otn oto otp otr ots ott p-p pbb pbe pbn pbo pbp pbr pbs pbt peb pee pen peo pep per pes pet pn- pnb pne pnn pno pnp pnr pns pnt pob poe pon poo pop por pos pot ppb ppe ppn ppo ppp ppr pps ppt prb pre prn pro prp prr prs prt ps- psb pse psn pso psp psr pss pst pt- ptb pte ptn pto ptp ptr pts ptt rbb rbe rbn rbo rbp rbr rbs rbt re- reb ree ren reo rep rer res ret rnb rnn rno rnp rnr rns rnt rob roe ron roo rop ror ros rot rpb rpe rpn rpo rpp rpr rps rpt rrb rrn rrp rrr rrs rrt rsb rse rsn rso rsp rsr rss rst rtb rte rtn rto rtp rtr rts rtt sbb sbe sbn sbo sbp sbr sbs sbt se- seb see sen seo sep ser ses set snb sne snn sno snp snr sns snt sob soe son soo sop sor sos sot spb spe spn spo spp spr sps spt sr- srb sre srn sro srp srr srs srt ss- ssb sse ssn sso ssp ssr sss sst stb ste stn sto stp str sts stt tbb tbe tbn tbo tbp tbr tbs tbt te- teb tee ten teo tep ter tes tet tnb tne tnn tno tnp tnr tns tnt to- tob toe ton too top tor tos tot tpb tpe tpn tpo tpp tpr tps tpt trb tre trn tro trp trr trs trt tsb tse tsn tso tsp tsr tss tst ttb tte ttn tto ttp ttr tts ttt