-er b-p bbb bbc bbe bbm bbn bbo bbp bbr bbs bcb bcc bce bcm bcn bco bcp bcr bcs be- beb bec bee bem ben beo bep ber bes bmb bmc bme bmm bmn bmo bmp bmr bms bnb bnc bne bnn bno bnp bnr bns bob boc boe bom bon boo bop bor bos bpb bpc bpe bpm bpn bpo bpp bpr bps brb bre brm brn bro brp brr brs bsb bsc bse bsm bsn bso bsp bsr bss c-- cbb cbc cbe cbm cbn cbo cbp cbr cbs ccb ccc cce ccm ccn cco ccp ccr ccs ce- ceb cec cee cem cen ceo cep cer ces cmb cmc cme cmm cmn cmo cmp cmr cms cn- cnb cnc cne cnm cnn cno cnp cnr cns co- cob coc coe com con coo cop cor cos cpb cpc cpe cpm cpn cpo cpp cpr cps crb crc cre crm crn cro crp crr crs csb csc cse csm csn cso csp csr css ebb ebc ebe ebm ebn ebo ebp ebr ebs ec- ecb ecc ece ecm ecn eco ecr ecs eeb eec eee eem een eeo eep eer ees em- emb emc eme emm emn emo emp emr ems en- enb enc ene enm enn eno enp enr ens eo- eob eoc eoe eom eon eoo eop eor eos ep- epb epc epe epm epn epo epp epr eps erb erc ere erm ern ero erp err ers es- esb esc ese esm esn eso esp esr ess m-o m-r mbb mbc mbe mbm mbo mbp mbr mbs mc- mcb mcc mce mcm mcn mco mcp mcr mcs meb mec mee mem men meo mep mer mes mmb mmc mme mmm mmn mmo mmp mmr mms mnb mnc mne mnm mnn mno mnp mnr mns mob moc moe mom mon moo mop mor mos mpb mpc mpe mpm mpn mpo mpp mpr mps mrb mrc mre mrm mrn mro mrp mrr mrs msb msc mse msm msn mso msp msr mss nbb nbc nbe nbm nbn nbo nbp nbr nbs ncb ncc nce ncm ncn nco ncp ncr ncs ne- neb nec nee nem nen neo nep ner nes nmb nmc nme nmm nmn nmo nmp nmr nms nnb nnc nne nnm nnn nno nnp nns no- nob noc noe nom non noo nop nor nos npb npc npe npm npn npo npp npr nps nrb nrc nre nrm nrn nro nrp nrr nrs nsb nsc nse nsm nsn nso nsp nsr nss ob- obb obc obe obm obn obo obp obr obs oc- ocb occ ocm ocn oco ocp ocr ocs oeb oec oee oem oen oeo oep oer oes om- omb omc ome omm omn omo omp omr oms on- onb onc one onn ono onp onr ons oo- oob ooc oom oon ooo oop oor oos op- opb opc ope opm opn opo opp opr ops or- orb orc ore orm orn oro orp orr ors os- osb osc ose osm osn oso osp osr oss p-p pbb pbc pbe pbm pbn pbo pbp pbr pbs pcb pcc pce pcm pcn pco pcp pcr pcs peb pec pee pem pen peo pep per pes pmb pmc pme pmm pmn pmo pmp pmr pms pn- pnb pnc pne pnm pnn pno pnp pnr pns pob poc poe pom pon poo pop por pos ppb ppc ppe ppm ppn ppo ppp ppr pps prb prc pre prm prn pro prp prr prs ps- psb psc pse psm psn pso psp psr pss rbb rbc rbe rbm rbn rbo rbp rbr rbs rcb rcc rce rcm rcn rco rcp rcr rcs re- reb rec ree rem ren reo rep rer res rmb rmc rme rmm rmn rmo rmp rmr rms rnb rnc rnm rnn rno rnp rnr rns rob roc roe rom ron roo rop ror ros rpb rpc rpe rpm rpn rpo rpp rpr rps rrb rrc rrm rrn rrp rrr rrs rsb rsc rse rsm rsn rso rsp rsr rss sbb sbc sbe sbm sbn sbo sbp sbr sbs scb scc sce scm scn sco scp scr scs se- seb sec see sem sen seo sep ser ses smb smc sme smm smn smo smp smr sms snb snc sne snm snn sno snp snr sns sob soc soe som son soo sop sor sos spb spc spe spm spn spo spp spr sps sr- srb src sre srm srn sro srp srr srs ss- ssb ssc sse ssm ssn sso ssp ssr sss