a-a a-c a-z aaa aac aae aan aap aaz ac- aca acc ace acn acp acz aea aec aee aen aep aez an- ana anc ane ann anp anz ap- apa apc ape apn app az- aza aze azn azp azz c-- caa cac cae can cap caz cca ccc cce ccn ccp ccz ce- cea cec cee cen cep cez cn- cna cnc cne cnn cnp cpa cpc cpe cpn cpp cpz cz- czc cze eaa eac eae ean eap eaz ec- eca ecc ece ecn eea eec eee een eep en- ena enc ene enn enp enz ep- epa epc epe epn epp epz eze ezz naa nac nae nan nap naz nca ncc nce ncn ncp ne- nea nec nee nen nep nez nna nnc nne nnn nnp nnz npa npc npe npn npp npz nze nzp nzz p-p paa pac pae pan pap paz pca pcc pce pcn pcp pea pec pee pen pep pez pn- pna pnc pne pnn pnp ppa ppc ppe ppn ppp ppz pzc pzp zaa zac zan zap zaz zce zea zec zee zen zep zez znc zne znn znp zpc zpe zpp zzz