a-a a-c a-z aaa aac aap aay aaz ac- aca acc acp acy acz ap- apa apc app apy ay- aya ayc ayp ayz az- aza azp azy azz c-- caa cac cap cay caz cca ccc ccp ccz cpa cpc cpp cpz cya cyc cyp cz- czc p-p paa pac pap pay paz pca pcc pcp ppa ppc ppp ppz py- pya pyc pzc pzp yaa yac yap yay yaz yca ycc ycp ycy ypa yyc yyy yyz yzy zaa zac zap zay zaz zpc zpp zzy zzz