-er b-p bbb bbe bbg bbo bbp bbr bbs bbt be- beb bee beg beo bep ber bes bet bgb bge bgg bgo bgp bgr bgs bgt bob boe bog boo bop bor bos bot bpb bpe bpg bpo bpp bpr bps bpt brb bre brg bro brp brr brs brt bsb bse bsg bso bsp bsr bss bst btb bte btg bto btp btr bts btt ebb ebe ebg ebo ebp ebr ebs ebt eeb eee eeg eeo eep eer ees eet egb ege egg ego egp egr egs egt eo- eob eoe eog eoo eop eor eos eot ep- epb epe epg epo epp epr eps ept erb ere erg ero erp err ers ert es- esb ese esg eso esp esr ess est etb ete etg eto etp etr ets ett g-p gbe gbg gbo gbp gbr gbs gbt ge- geb gee geg geo gep ger ges get ggb ggg ggo ggp ggr ggs ggt gob goe gog goo gop gor gos got gpb gpe gpg gpo gpp gpr gps gpt grb gre grg gro grp grr grs grt gsb gse gsg gso gsp gsr gss gst gtb gte gtg gto gtp gtr gts gtt ob- obb obe obg obo obp obr obs obt oeb oee oeg oeo oep oer oes oet oge ogg ogo ogp ogs ogt oo- oob oog ooo oop oor oos oot op- opb ope opg opo opp opr ops opt or- orb ore org oro orp orr ors ort os- osb ose osg oso osp osr oss ost ot- otb ote otg oto otp otr ots ott p-p pbb pbe pbg pbo pbp pbr pbs pbt peb pee peg peo pep per pes pet pgb pge pgg pgo pgp pgr pgs pgt pob poe pog poo pop por pos pot ppb ppe ppg ppo ppp ppr pps ppt prb pre prg pro prp prr prs prt ps- psb pse psg pso psp psr pss pst pt- ptb pte ptg pto ptp ptr pts ptt rbb rbe rbg rbo rbp rbr rbs rbt re- reb ree reg reo rep rer res ret rgb rge rgg rgo rgp rgr rgs rgt rob roe rog roo rop ror ros rot rpb rpe rpg rpo rpp rpr rps rpt rrb rrg rrp rrr rrs rrt rsb rse rsg rso rsp rsr rss rst rtb rte rtg rto rtp rtr rts rtt sbb sbe sbg sbo sbp sbr sbs sbt se- seb see seg seo sep ser ses set sgb sge sgg sgo sgp sgr sgs sgt sob soe sog soo sop sor sos sot spb spe spg spo spp spr sps spt sr- srb sre srg sro srp srr srs srt ss- ssb sse ssg sso ssp ssr sss sst stb ste stg sto stp str sts stt tbb tbe tbg tbo tbp tbr tbs tbt te- teb tee teg teo tep ter tes tet tgb tge tgg tgo tgp tgr tgs tgt to- tob toe tog too top tor tos tot tpb tpe tpg tpo tpp tpr tps tpt trb tre trg tro trp trr trs trt tsb tse tsg tso tsp tsr tss tst ttb tte ttg tto ttp ttr tts ttt