a-a a-z aaa aad aae aaf aaz ad- ada add ade adf adz aea aed aee aef aez af- afa afd afe aff afz az- aza azd aze azf azz daa dad dae daf daz dda ddd dde ddf ddz de- dea ded dee def dez dfa dfd dfe dff dfz dza dzd dze eaa ead eae eaf eaz ed- eda edd ede edf eea eed eee eef ef- efa efd efe eff eze ezf ezz faa fad fae faf faz fda fdd fde fdf fea fed fee fef fez ffa ffd ffe fff ffz fzd zaa zad zaf zaz zdf zea zed zee zef zez zfa zfd zzz