-ic a-a a-b a-c a-i aaa aab aac aaf aai ab- aba abb abc abf abi ac- aca acb acc acf aci af- afa afb afc aff afi ai- aia aib aic aif aii baa bab bac baf bai bba bbb bbc bbf bbi bca bcb bcc bcf bci bfa bfb bfc bff bfi bi- bia bib bic bif bii c-- caa cab cac caf cai cba cbb cbc cbf cbi cca ccb ccc ccf cci cfa cfb cfc cff cfi ci- cia cib cic cif cii faa fab fac faf fai fba fbb fbc fbf fbi fca fcb fcc fcf fci ffa ffc fff ffi fia fib fic fif fii i-f ia- iaa iab iac iaf iai iba ibb ibc ibf ibi ica icb icc icf ici ifa ifb ifc iff ifi iia iib iic iif iii