-ic a-a a-b a-c a-i aaa aab aac aai aax ab- aba abb abc abi abx ac- aca acb acc aci acx ai- aia aib aic aii aix ax- axa axi axx baa bab bac bai bax bba bbb bbc bbi bbx bca bcb bcc bci bcx bi- bia bib bic bii bix bxb bxi bxx c-- caa cab cac cai cax cba cbb cbc cbi cbx cca ccb ccc cci ccx ci- cia cib cic cii cix cxc cxi cxx ia- iaa iab iac iai iba ibb ibc ibi ibx ica icb icc ici iia iib iic iii iix ixc ixi xaa xac xbc xbx xcb xci xcx xia xic xii xix xxi xxx