a-a a-c a-z aaa aac aae aao aaz ac- aca acc ace aco acz aea aec aee aeo aez aoa aoc aoe aoo az- aza aze azo azz c-- caa cac cae cao caz cca ccc cce cco ccz ce- cea cec cee ceo cez co- coa coc coe coo coz cz- czc cze czo eaa eac eae eao eaz ec- eca ecc ece eco eea eec eee eeo eo- eoa eoc eoe eoo eze ezo ezz oaa oac oae oao oc- oca occ oco ocz oea oec oee oeo oo- ooa ooc ooo oza oze ozo ozz zaa zac zao zaz zce zco zea zec zee zeo zez zo- zoa zoc zoe zoo zzz