a-a a-c a-z aaa aac aad aan aaz ac- aca acc acd acn acz ad- ada adc add adn adz an- ana anc and ann anz az- aza azd azn azz c-- caa cac cad can caz cca ccc ccd ccn ccz cda cdc cdd cdn cdz cn- cna cnc cnd cnn cz- czc czd daa dac dad dan daz dca dcc dcd dcn dda ddc ddd ddn ddz dna dnc dnd dnn dnz dza dzd naa nac nad nan naz nca ncc ncd ncn nda ndc ndd ndn nna nnc nnn nnz nzd nzz zaa zac zad zan zaz znc znd znn zzz