-er -ic a-a a-c a-i aaa aac aae aai aap aar ac- aca acc ace aci acp acr aea aec aee aei aep aer ai- aia aic aie aii aip air ap- apa apc ape api app apr ar- ara arc are ari arp arr c-- caa cac cae cai cap car cca ccc cce cci ccp ccr ce- cea cec cee cei cep cer ci- cia cic cie cii cip cir cpa cpc cpe cpi cpp cpr cra crc cre cri crp crr eaa eac eae eai eap ear ec- eca ecc ece eci ecr eea eec eee eep eer eia eic eie eii eip eir ep- epa epc epe epi epp epr era erc ere eri erp err ia- iaa iac iae iai iap iar ica icc ice ici icp icr ie- iea iec iee iei iep ier iia iic iie iii iip iir ipa ipc ipe ipi ipp ipr ir- ira irc ire iri irp irr p-p paa pac pae pai pap par pca pcc pce pci pcp pcr pea pec pee pei pep per pia pic pie pii pip pir ppa ppc ppe ppi ppp ppr pra prc pre pri prp prr ra- raa rac rae rai rap rar rca rcc rce rci rcp rcr re- rea rec ree rei rep rer ria ric rie rii rip rir rpa rpc rpe rpi rpp rpr rra rrc rri rrp rrr