-ic a-a a-c a-i aaa aac aae aai aax ac- aca acc ace aci acx aea aec aee aei aex ai- aia aic aie aii aix ax- axa axe axi axx c-- caa cac cae cai cax cca ccc cce cci ccx ce- cea cec cee cei cex ci- cia cic cie cii cix cxc cxi cxx eaa eac eae eai eax ec- eca ecc ece eci ecx eea eec eee eex eia eic eie eii eix ex- exa exc exe exi exx ia- iaa iac iae iai ica icc ice ici ie- iea iec iee iei iex iia iic iie iii iix ixc ixe ixi xaa xac xci xcx xee xex xia xic xie xii xix xxi xxx