-ic a-a a-b a-c a-i aaa aab aac aae aai aan ab- aba abb abc abe abi abn ac- aca acb acc ace aci acn aea aeb aec aee aei aen ai- aia aib aic aie aii ain an- ana anb anc ane ani ann baa bab bac bae bai ban bba bbb bbc bbe bbi bbn bca bcb bcc bce bci bcn be- bea beb bec bee bei ben bi- bia bib bic bie bii bin bna bnb bnc bne bni bnn c-- caa cab cac cae cai can cba cbb cbc cbe cbi cbn cca ccb ccc cce cci ccn ce- cea ceb cec cee cei cen ci- cia cib cic cie cii cin cn- cna cnb cnc cne cni cnn eaa eab eac eae eai ean eba ebb ebc ebe ebi ebn ec- eca ecb ecc ece eci ecn eea eeb eec eee een eia eib eic eie eii ein en- ena enb enc ene eni enn ia- iaa iab iac iae iai ian iba ibb ibc ibe ibi ibn ica icb icc ice ici icn ie- iea iec iee iei ien iia iib iic iie iii iin in- ina inb inc ine ini inn n-i naa nab nac nae nai nan nba nbb nbc nbe nbi nbn nca ncb ncc nce nci ncn ne- nea neb nec nee nei nen nia nib nic nie nii nin nna nnb nnc nne nni nnn