-er b-p bbb bbc bbe bbm bbo bbp bbr bbs bcb bcc bce bcm bco bcp bcr bcs be- beb bec bee bem beo bep ber bes bmb bmc bme bmm bmo bmp bmr bms bob boc boe bom boo bop bor bos bpb bpc bpe bpm bpo bpp bpr bps brb bre brm bro brp brr brs bsb bsc bse bsm bso bsp bsr bss c-- cbb cbc cbe cbm cbo cbp cbr cbs ccb ccc cce ccm cco ccp ccr ccs ce- ceb cec cee cem ceo cep cer ces cmb cmc cme cmm cmo cmp cmr cms co- cob coc coe com coo cop cor cos cpb cpc cpe cpm cpo cpp cpr cps crb crc cre crm cro crp crr crs csb csc cse csm cso csp csr css ebb ebc ebe ebm ebo ebp ebr ebs ec- ecb ecc ece ecm eco ecr ecs eeb eec eee eem eeo eep eer ees em- emb emc eme emm emo emp emr ems eo- eob eoc eoe eom eoo eop eor eos ep- epb epc epe epm epo epp epr eps erb erc ere erm ero erp err ers es- esb esc ese esm eso esp esr ess m-o m-r mbb mbc mbe mbm mbo mbp mbr mbs mc- mcb mcc mce mcm mco mcp mcr mcs meb mec mee mem meo mep mer mes mmb mmc mme mmm mmo mmp mmr mms mob moc moe mom moo mop mor mos mpb mpc mpe mpm mpo mpp mpr mps mrb mrc mre mrm mro mrp mrr mrs msb msc mse msm mso msp msr mss ob- obb obc obe obm obo obp obr obs oc- ocb occ ocm oco ocp ocr ocs oeb oec oee oem oeo oep oer oes om- omb omc ome omm omo omp omr oms oo- oob ooc oom ooo oop oor oos op- opb opc ope opm opo opp opr ops or- orb orc ore orm oro orp orr ors os- osb osc ose osm oso osp osr oss p-p pbb pbc pbe pbm pbo pbp pbr pbs pcb pcc pce pcm pco pcp pcr pcs peb pec pee pem peo pep per pes pmb pmc pme pmm pmo pmp pmr pms pob poc poe pom poo pop por pos ppb ppc ppe ppm ppo ppp ppr pps prb prc pre prm pro prp prr prs ps- psb psc pse psm pso psp psr pss rbb rbc rbe rbm rbo rbp rbr rbs rcb rcc rce rcm rco rcp rcr rcs re- reb rec ree rem reo rep rer res rmb rmc rme rmm rmo rmp rmr rms rob roc roe rom roo rop ror ros rpb rpc rpe rpm rpo rpp rpr rps rrb rrc rrm rrp rrr rrs rsb rsc rse rsm rso rsp rsr rss sbb sbc sbe sbm sbo sbp sbr sbs scb scc sce scm sco scp scr scs se- seb sec see sem seo sep ser ses smb smc sme smm smo smp smr sms sob soc soe som soo sop sor sos spb spc spe spm spo spp spr sps sr- srb src sre srm sro srp srr srs ss- ssb ssc sse ssm sso ssp ssr sss