-er b-p bbb bbc bbe bbm bbo bbp bbr bbt bcb bcc bce bcm bco bcp bcr bct be- beb bec bee bem beo bep ber bet bmb bmc bme bmm bmo bmp bmr bmt bob boc boe bom boo bop bor bot bpb bpc bpe bpm bpo bpp bpr bpt brb bre brm bro brp brr brt btb btc bte btm bto btp btr btt c-- cbb cbc cbe cbm cbo cbp cbr cbt ccb ccc cce ccm cco ccp ccr cct ce- ceb cec cee cem ceo cep cer cet cmb cmc cme cmm cmo cmp cmr cmt co- cob coc coe com coo cop cor cot cpb cpc cpe cpm cpo cpp cpr cpt crb crc cre crm cro crp crr crt ctb ctc cte ctm cto ctp ctr ctt ebb ebc ebe ebm ebo ebp ebr ebt ec- ecb ecc ece ecm eco ecr ect eeb eec eee eem eeo eep eer eet em- emb emc eme emm emo emp emr emt eo- eob eoc eoe eom eoo eop eor eot ep- epb epc epe epm epo epp epr ept erb erc ere erm ero erp err ert etb etc ete etm eto etp etr ett m-o m-r mbb mbc mbe mbm mbo mbp mbr mbt mc- mcb mcc mce mcm mco mcp mcr mct meb mec mee mem meo mep mer met mmb mmc mme mmm mmo mmp mmr mmt mob moc moe mom moo mop mor mot mpb mpc mpe mpm mpo mpp mpr mpt mrb mrc mre mrm mro mrp mrr mrt mtb mtc mte mtm mto mtp mtr mtt ob- obb obc obe obm obo obp obr obt oc- ocb occ ocm oco ocp ocr oct oeb oec oee oem oeo oep oer oet om- omb omc ome omm omo omp omr omt oo- oob ooc oom ooo oop oor oot op- opb opc ope opm opo opp opr opt or- orb orc ore orm oro orp orr ort ot- otb otc ote otm oto otp otr ott p-p pbb pbc pbe pbm pbo pbp pbr pbt pcb pcc pce pcm pco pcp pcr pct peb pec pee pem peo pep per pet pmb pmc pme pmm pmo pmp pmr pmt pob poc poe pom poo pop por pot ppb ppc ppe ppm ppo ppp ppr ppt prb prc pre prm pro prp prr prt pt- ptb ptc pte ptm pto ptp ptr ptt rbb rbc rbe rbm rbo rbp rbr rbt rcb rcc rce rcm rco rcp rcr rct re- reb rec ree rem reo rep rer ret rmb rmc rme rmm rmo rmp rmr rmt rob roc roe rom roo rop ror rot rpb rpc rpe rpm rpo rpp rpr rpt rrb rrc rrm rrp rrr rrt rtb rtc rte rtm rto rtp rtr rtt tbb tbc tbe tbm tbo tbp tbr tbt tcb tcc tce tcm tco tcp tcr tct te- teb tec tee tem teo tep ter tet tmb tmc tme tmm tmo tmp tmr tmt to- tob toc toe tom too top tor tot tpb tpc tpe tpm tpo tpp tpr tpt trb trc tre trm tro trp trr trt ttb ttc tte ttm tto ttp ttr ttt