a-a a-c aaa aac aad aae aan aax ac- aca acc acd ace acn acx ad- ada adc add ade adn adx aea aec aed aee aen aex an- ana anc and ane ann anx ax- axa axe axn axx c-- caa cac cad cae can cax cca ccc ccd cce ccn ccx cda cdc cdd cde cdn cdx ce- cea cec ced cee cen cex cn- cna cnc cnd cne cnn cnx cxc cxx daa dac dad dae dan dax dca dcc dcd dce dcn dcx dda ddc ddd dde ddn ddx de- dea dec ded dee den dex dna dnc dnd dne dnn dxc dxd dxn dxx eaa eac ead eae ean eax ec- eca ecc ecd ece ecn ecx ed- eda edc edd ede edn edx eea eec eed eee een eex en- ena enc end ene enn ex- exa exc exd exe exx naa nac nad nae nan nax nca ncc ncd nce ncn ncx nda ndc ndd nde ndn ne- nea nec ned nee nen nex nna nnc nne nnn nxc nxd xaa xac xad xan xcd xcx xda xdc xde xed xee xen xex xna xnc xxx