a-a a-c aaa aac aae aaf aap ac- aca acc ace acf acp aea aec aee aef aep af- afa afc afe aff afp ap- apa apc ape apf app c-- caa cac cae caf cap cca ccc cce ccf ccp ce- cea cec cee cef cep cfa cfc cfe cff cfp cpa cpc cpe cpf cpp eaa eac eae eaf eap ec- eca ecc ece ecf eea eec eee eef eep ef- efa efc efe eff efp ep- epa epc epe epf epp faa fac fae faf fap fca fcc fce fcf fcp fea fec fee fef fep ffa ffc ffe fff ffp fpa fpc fpe fpp p-p paa pac pae paf pap pca pcc pce pcf pcp pea pec pee pef pep pfa pfc pfe pff pfp ppa ppc ppe ppf ppp