-ic a-a a-b a-c a-i aaa aab aac aai aan aao ab- aba abb abc abi abn abo ac- aca acb acc aci acn aco ai- aia aib aic aii ain aio an- ana anb anc ani ann ano aoa aob aoc aoi aon aoo baa bab bac bai ban bao bba bbb bbc bbi bbn bbo bca bcb bcc bci bcn bco bi- bia bib bic bii bin bio bna bnb bnc bni bnn bno boa bob boc boi bon boo c-- caa cab cac cai can cao cba cbb cbc cbi cbn cbo cca ccb ccc cci ccn cco ci- cia cib cic cii cin cio cn- cna cnb cnc cni cnn cno co- coa cob coc coi con coo ia- iaa iab iac iai ian iao iba ibb ibc ibi ibn ibo ica icb icc ici icn ico iia iib iic iii iin iio in- ina inb inc ini inn ino io- ioa iob ioc ioi ion ioo n-i naa nab nac nai nan nao nba nbb nbc nbi nbn nbo nca ncb ncc nci ncn nco nia nib nic nii nin nio nna nnb nnc nni nnn nno no- noa nob noc noi non noo o-i oaa oab oac oai oan oao ob- oba obb obc obi obn obo oc- oca ocb occ oci ocn oco oia oib oic oii oin oio on- ona onb onc oni onn ono oo- ooa oob ooc ooi oon ooo