-er a-a a-c a-z aaa aac aae aap aar aaz ac- aca acc ace acp acr acz aea aec aee aep aer aez ap- apa apc ape app apr ar- ara arc are arp arr arz az- aza aze azp azz c-- caa cac cae cap car caz cca ccc cce ccp ccr ccz ce- cea cec cee cep cer cez cpa cpc cpe cpp cpr cpz cra crc cre crp crr crz cz- czc cze eaa eac eae eap ear eaz ec- eca ecc ece ecr eea eec eee eep eer ep- epa epc epe epp epr epz era erc ere erp err erz eze ezr ezz p-p paa pac pae pap par paz pca pcc pce pcp pcr pea pec pee pep per pez ppa ppc ppe ppp ppr ppz pra prc pre prp prr prz pzc pzp ra- raa rac rae rap rar raz rca rcc rce rcp rcr re- rea rec ree rep rer rez rpa rpc rpe rpp rpr rpz rra rrc rrp rrr rza rze zaa zac zap zar zaz zce zea zec zee zep zer zez zpc zpe zpp zpr zrp zzr zzz