-er a-a a-c aaa aac aae aan aap aar aas ac- aca acc ace acn acp acr acs aea aec aee aen aep aer aes an- ana anc ane ann anp anr ans ap- apa apc ape apn app apr aps ar- ara arc are arn arp arr ars as- asa asc ase asn asp asr ass c-- caa cac cae can cap car cas cca ccc cce ccn ccp ccr ccs ce- cea cec cee cen cep cer ces cn- cna cnc cne cnn cnp cnr cns cpa cpc cpe cpn cpp cpr cps cra crc cre crn crp crr crs csa csc cse csn csp csr css eaa eac eae ean eap ear eas ec- eca ecc ece ecn ecr ecs eea eec eee een eep eer ees en- ena enc ene enn enp enr ens ep- epa epc epe epn epp epr eps era erc ere ern erp err ers es- esa esc ese esn esp esr ess naa nac nae nan nap nar nas nca ncc nce ncn ncp ncr ncs ne- nea nec nee nen nep ner nes nna nnc nne nnn nnp nns npa npc npe npn npp npr nps nra nrc nre nrn nrp nrr nrs nsa nsc nse nsn nsp nsr nss p-p paa pac pae pan pap par pas pca pcc pce pcn pcp pcr pcs pea pec pee pen pep per pes pn- pna pnc pne pnn pnp pnr pns ppa ppc ppe ppn ppp ppr pps pra prc pre prn prp prr prs ps- psa psc pse psn psp psr pss ra- raa rac rae ran rap rar ras rca rcc rce rcn rcp rcr rcs re- rea rec ree ren rep rer res rna rnc rnn rnp rnr rns rpa rpc rpe rpn rpp rpr rps rra rrc rrn rrp rrr rrs rsa rsc rse rsn rsp rsr rss saa sac sae san sap sar sas sca scc sce scn scp scr scs se- sea sec see sen sep ser ses sna snc sne snn snp snr sns spa spc spe spn spp spr sps sr- sra src sre srn srp srr srs ss- ssa ssc sse ssn ssp ssr sss