-ic a-a a-b a-c a-i aaa aab aac aad aai aak aao aar ab- aba abb abc abd abi abk abo abr ac- aca acb acc acd aci ack aco acr ad- ada adb adc add adi adk ado adr ai- aia aib aic aid aii aik aio air aka akb akc akd aki akk ako akr aoa aob aoc aod aoi aok aoo aor ar- ara arb arc ard ari ark aro arr baa bab bac bad bai bak bao bar bba bbb bbc bbd bbi bbk bbo bbr bca bcb bcc bcd bci bck bco bcr bda bdb bdc bdd bdi bdk bdo bdr bi- bia bib bic bid bii bik bio bir bka bkb bkc bkk bko bkr boa bob boc bod boi bok boo bor bra brb brd bri brk bro brr c-- caa cab cac cad cai cak cao car cba cbb cbc cbd cbi cbk cbo cbr cca ccb ccc ccd cci cck cco ccr cda cdb cdc cdd cdi cdk cdo cdr ci- cia cib cic cid cii cik cio cir cka ckb ckc ckd cki cko co- coa cob coc cod coi cok coo cor cra crb crc crd cri crk cro crr daa dab dac dad dai dak dao dar dba dbb dbc dbd dbi dbk dbo dbr dca dcb dcc dcd dci dck dco dcr dda ddb ddc ddd ddi ddk ddo ddr di- dia dib dic did dii dik dio dir dka dkb dkc dki dkk dko dkr doa dob doc dod doi dok doo dor dra drb drc drd dri drk dro drr i-d ia- iaa iab iac iad iai iao iar iba ibb ibc ibd ibi ibk ibo ibr ica icb icc icd ici ick ico icr ida idb idc idd idi idk ido idr iia iib iic iid iii iio iir ika ikb ikc iki ikk iko ikr io- ioa iob ioc iod ioi ioo ior ir- ira irb irc ird iri irk iro irr ka- kaa kab kac kad kai kak kao kar kba kbb kbc kbd kbi kbk kbo kbr kca kcb kcc kcd kci kck kcr kda kdb kdc kdk kdo kdr kia kib kic kid kii kik kio kir kkb kkc kki kkk kkr koa kob koc kod koi kok koo kor kra krc krd kri krk kro krr o-i oaa oab oac oad oai oak oao oar ob- oba obb obc obd obi obk obo obr oc- oca ocb occ ocd oci ock oco ocr oda odb odc odd odi odo odr oia oib oic oid oii oik oio oir oka okb okc okd oki okk oko okr oo- ooa oob ooc ood ooi ook ooo oor or- ora orb orc ord ori ork oro orr ra- raa rab rac rad rai rak rao rar rba rbb rbc rbd rbi rbk rbo rbr rca rcb rcc rcd rci rco rcr rda rdb rdc rdd rdi rdo rdr ria rib ric rid rii rik rio rir rkb rkc rkk rko roa rob roc rod roi rok roo ror rra rrb rrc rrd rri rrk rrr