-er a-a a-c a-z aaa aac aae aar aaz ac- aca acc ace acr acz aea aec aee aer aez ar- ara arc are arr arz az- aza aze azz c-- caa cac cae car caz cca ccc cce ccr ccz ce- cea cec cee cer cez cra crc cre crr crz cz- czc cze eaa eac eae ear eaz ec- eca ecc ece ecr eea eec eee eer era erc ere err erz eze ezr ezz ra- raa rac rae rar raz rca rcc rce rcr re- rea rec ree rer rez rra rrc rrr rza rze zaa zac zar zaz zce zea zec zee zer zez zzr zzz