a-a a-c a-z aaa aac aae aak aaz ac- aca acc ace ack acz aea aec aee aek aez aka akc ake akk az- aza aze azz c-- caa cac cae cak caz cca ccc cce cck ccz ce- cea cec cee cek cez cka ckc cz- czc cze czk eaa eac eae eak eaz ec- eca ecc ece eck eea eec eee eek eka ekc eke eze ezz k-z ka- kaa kac kae kak kaz kca kcc kce kck ke- kea kec kee kek kez kkc kke kkk zaa zac zak zaz zce zea zec zee zek zez zka zzz