a-a a-c aaa aac aad aan aap ac- aca acc acd acn acp ad- ada adc add adn adp an- ana anc and ann anp ap- apa apc apd apn app c-- caa cac cad can cap cca ccc ccd ccn ccp cda cdc cdd cdn cdp cn- cna cnc cnd cnn cnp cpa cpc cpd cpn cpp daa dac dad dan dap dca dcc dcd dcn dcp dda ddc ddd ddn ddp dna dnc dnd dnn dnp dpa dpc dpd dpn dpp naa nac nad nan nap nca ncc ncd ncn ncp nda ndc ndd ndn ndp nna nnc nnn nnp npa npc npd npn npp p-p paa pac pad pan pap pca pcc pcd pcn pcp pda pdc pdd pdn pdp pn- pna pnc pnd pnn pnp ppa ppc ppd ppn ppp