-er c-- ccc cce ccn cco ccp ccr ccs ce- cec cee cen ceo cep cer ces cn- cnc cne cnn cno cnp cnr cns co- coc coe con coo cop cor cos cpc cpe cpn cpo cpp cpr cps crc cre crn cro crp crr crs csc cse csn cso csp csr css ec- ecc ece ecn eco ecr ecs eec eee een eeo eep eer ees en- enc ene enn eno enp enr ens eo- eoc eoe eon eoo eop eor eos ep- epc epe epn epo epp epr eps erc ere ern ero erp err ers es- esc ese esn eso esp esr ess ncc nce ncn nco ncp ncr ncs ne- nec nee nen neo nep ner nes nnc nne nnn nno nnp nns no- noc noe non noo nop nor nos npc npe npn npo npp npr nps nrc nre nrn nro nrp nrr nrs nsc nse nsn nso nsp nsr nss oc- occ ocn oco ocp ocr ocs oec oee oen oeo oep oer oes on- onc one onn ono onp onr ons oo- ooc oon ooo oop oor oos op- opc ope opn opo opp opr ops or- orc ore orn oro orp orr ors os- osc ose osn oso osp osr oss p-p pcc pce pcn pco pcp pcr pcs pec pee pen peo pep per pes pn- pnc pne pnn pno pnp pnr pns poc poe pon poo pop por pos ppc ppe ppn ppo ppp ppr pps prc pre prn pro prp prr prs ps- psc pse psn pso psp psr pss rcc rce rcn rco rcp rcr rcs re- rec ree ren reo rep rer res rnc rnn rno rnp rnr rns roc roe ron roo rop ror ros rpc rpe rpn rpo rpp rpr rps rrc rrn rrp rrr rrs rsc rse rsn rso rsp rsr rss scc sce scn sco scp scr scs se- sec see sen seo sep ser ses snc sne snn sno snp snr sns soc soe son soo sop sor sos spc spe spn spo spp spr sps sr- src sre srn sro srp srr srs ss- ssc sse ssn sso ssp ssr sss