-er a-a a-c aaa aac aae aan aap aar ac- aca acc ace acn acp acr aea aec aee aen aep aer an- ana anc ane ann anp anr ap- apa apc ape apn app apr ar- ara arc are arn arp arr c-- caa cac cae can cap car cca ccc cce ccn ccp ccr ce- cea cec cee cen cep cer cn- cna cnc cne cnn cnp cnr cpa cpc cpe cpn cpp cpr cra crc cre crn crp crr eaa eac eae ean eap ear ec- eca ecc ece ecn ecr eea eec eee een eep eer en- ena enc ene enn enp enr ep- epa epc epe epn epp epr era erc ere ern erp err naa nac nae nan nap nar nca ncc nce ncn ncp ncr ne- nea nec nee nen nep ner nna nnc nne nnn nnp npa npc npe npn npp npr nra nrc nre nrn nrp nrr p-p paa pac pae pan pap par pca pcc pce pcn pcp pcr pea pec pee pen pep per pn- pna pnc pne pnn pnp pnr ppa ppc ppe ppn ppp ppr pra prc pre prn prp prr ra- raa rac rae ran rap rar rca rcc rce rcn rcp rcr re- rea rec ree ren rep rer rna rnc rnn rnp rnr rpa rpc rpe rpn rpp rpr rra rrc rrn rrp rrr