-ic a-a a-b a-c a-i aaa aab aac aad aai aao aar ab- aba abb abc abd abi abo abr ac- aca acb acc acd aci aco acr ad- ada adb adc add adi ado adr ai- aia aib aic aid aii aio air aoa aob aoc aod aoi aoo aor ar- ara arb arc ard ari aro arr baa bab bac bad bai bao bar bba bbb bbc bbd bbi bbo bbr bca bcb bcc bcd bci bco bcr bda bdb bdc bdd bdi bdo bdr bi- bia bib bic bid bii bio bir boa bob boc bod boi boo bor bra brb brd bri bro brr c-- caa cab cac cad cai cao car cba cbb cbc cbd cbi cbo cbr cca ccb ccc ccd cci cco ccr cda cdb cdc cdd cdi cdo cdr ci- cia cib cic cid cii cio cir co- coa cob coc cod coi coo cor cra crb crc crd cri cro crr daa dab dac dad dai dao dar dba dbb dbc dbd dbi dbo dbr dca dcb dcc dcd dci dco dcr dda ddb ddc ddd ddi ddo ddr di- dia dib dic did dii dio dir doa dob doc dod doi doo dor dra drb drc drd dri dro drr i-d ia- iaa iab iac iad iai iao iar iba ibb ibc ibd ibi ibo ibr ica icb icc icd ici ico icr ida idb idc idd idi ido idr iia iib iic iid iii iio iir io- ioa iob ioc iod ioi ioo ior ir- ira irb irc ird iri iro irr o-i oaa oab oac oad oai oao oar ob- oba obb obc obd obi obo obr oc- oca ocb occ ocd oci oco ocr oda odb odc odd odi odo odr oia oib oic oid oii oio oir oo- ooa oob ooc ood ooi ooo oor or- ora orb orc ord ori oro orr ra- raa rab rac rad rai rao rar rba rbb rbc rbd rbi rbo rbr rca rcb rcc rcd rci rco rcr rda rdb rdc rdd rdi rdo rdr ria rib ric rid rii rio rir roa rob roc rod roi roo ror rra rrb rrc rrd rri rrr