-er c-- ccc ccd cce cck cco ccp ccr ccs cdc cdd cde cdk cdo cdp cdr cds ce- cec ced cee cek ceo cep cer ces ckc ckd cko cks co- coc cod coe cok coo cop cor cos cpc cpd cpe cpk cpo cpp cpr cps crc crd cre crk cro crp crr crs csc csd cse csk cso csp csr css dcc dcd dce dck dco dcp dcr dcs ddc ddd dde ddk ddo ddp ddr dds de- dec ded dee dek deo dep der des dkc dke dkk dko dkp dkr dks doc dod doe dok doo dop dor dos dpc dpd dpe dpk dpo dpp dpr dps drc drd dre drk dro drp drr drs dsc dsd dse dsk dso dsp dsr dss ec- ecc ecd ece eck eco ecr ecs ed- edc edd ede edk edo edp edr eds eec eed eee eek eeo eep eer ees ekc ekd eke eko ekp ekr eks eo- eoc eod eoe eok eoo eop eor eos ep- epc epd epe epo epp epr eps erc erd ere erk ero erp err ers es- esc esd ese esk eso esp esr ess kcc kcd kce kck kcp kcr kcs kdc kde kdk kdo kdp kdr kds ke- kec ked kee kek keo kep ker kes kkc kke kkk kkp kkr kks koc kod koe kok koo kop kor kos kpc kpd kpe kpk kpo kpp kpr kps krc krd krk kro krp krr krs ksc ksd kse ksk kso ksp ksr kss oc- occ ocd ock oco ocp ocr ocs odc odd ode odo odp odr ods oec oed oee oeo oep oer oes okc okd oke okk oko okp okr oks oo- ooc ood ook ooo oop oor oos op- opc opd ope opk opo opp opr ops or- orc ord ore ork oro orp orr ors os- osc osd ose osk oso osp osr oss p-p pcc pcd pce pck pco pcp pcr pcs pdc pdd pde pdk pdo pdp pdr pds pec ped pee pek peo pep per pes pkc pkd pke pko pkp pkr pks poc pod poe pok poo pop por pos ppc ppd ppe ppk ppo ppp ppr pps prc prd pre prk pro prp prr prs ps- psc psd pse psk pso psp psr pss rcc rcd rce rco rcp rcr rcs rdc rdd rde rdo rdp rdr rds re- rec red ree rek reo rep rer res rkc rke rkk rko rkp rks roc rod roe rok roo rop ror ros rpc rpd rpe rpk rpo rpp rpr rps rrc rrd rrk rrp rrr rrs rsc rsd rse rsk rso rsp rsr rss scc scd sce sck sco scp scr scs sdc sdd sde sdk sdo sdp sdr sds se- sec sed see sek seo sep ser ses sk- skc skd ske skk sko skp skr sks soc sod soe sok soo sop sor sos spc spd spe spk spo spp spr sps sr- src srd sre srk sro srp srr srs ss- ssc ssd sse ssk sso ssp ssr sss