-ic a-a a-b a-c a-i aaa aab aac aai aan aao aas ab- aba abb abc abi abn abo abs ac- aca acb acc aci acn aco acs ai- aia aib aic aii ain aio ais an- ana anb anc ani ann ano ans aoa aob aoc aoi aon aoo aos as- asa asb asc asi asn aso ass baa bab bac bai ban bao bas bba bbb bbc bbi bbn bbo bbs bca bcb bcc bci bcn bco bcs bi- bia bib bic bii bin bio bis bna bnb bnc bni bnn bno bns boa bob boc boi bon boo bos bsa bsb bsc bsi bsn bso bss c-- caa cab cac cai can cao cas cba cbb cbc cbi cbn cbo cbs cca ccb ccc cci ccn cco ccs ci- cia cib cic cii cin cio cis cn- cna cnb cnc cni cnn cno cns co- coa cob coc coi con coo cos csa csb csc csi csn cso css ia- iaa iab iac iai ian iao ias iba ibb ibc ibi ibn ibo ibs ica icb icc ici icn ico ics iia iib iic iii iin iio iis in- ina inb inc ini inn ino ins io- ioa iob ioc ioi ion ioo ios is- isa isb isc isi isn iso iss n-i naa nab nac nai nan nao nas nba nbb nbc nbi nbn nbo nbs nca ncb ncc nci ncn nco ncs nia nib nic nii nin nio nis nna nnb nnc nni nnn nno nns no- noa nob noc noi non noo nos nsa nsb nsc nsi nsn nso nss o-i oaa oab oac oai oan oao oas ob- oba obb obc obi obn obo obs oc- oca ocb occ oci ocn oco ocs oia oib oic oii oin oio ois on- ona onb onc oni onn ono ons oo- ooa oob ooc ooi oon ooo oos os- osa osb osc osi osn oso oss saa sab sac sai san sao sas sba sbb sbc sbi sbn sbo sbs sca scb scc sci scn sco scs sia sib sic sii sin sio sis sna snb snc sni snn sno sns soa sob soc soi son soo sos ss- ssa ssb ssc ssi ssn sso sss