-ic a-a a-b a-c a-i a-t aaa aab aac aai aao aar aat ab- aba abb abc abi abo abr abt ac- aca acb acc aci aco acr act ai- aia aib aic aii aio air ait aoa aob aoc aoi aoo aor aot ar- ara arb arc ari aro arr art at- ata atb atc ati ato atr att baa bab bac bai bao bar bat bba bbb bbc bbi bbo bbr bbt bca bcb bcc bci bco bcr bct bi- bia bib bic bii bio bir bit boa bob boc boi boo bor bot bra brb bri bro brr brt bta btb btc bti bto btr btt c-- caa cab cac cai cao car cat cba cbb cbc cbi cbo cbr cbt cca ccb ccc cci cco ccr cct ci- cia cib cic cii cio cir cit co- coa cob coc coi coo cor cot cra crb crc cri cro crr crt cta ctb ctc cti cto ctr ctt ia- iaa iab iac iai iao iar iat iba ibb ibc ibi ibo ibr ibt ica icb icc ici ico icr ict iia iib iic iii iio iir iit io- ioa iob ioc ioi ioo ior iot ir- ira irb irc iri iro irr irt ita itb itc iti ito itt o-i oaa oab oac oai oao oar oat ob- oba obb obc obi obo obr obt oc- oca ocb occ oci oco ocr oct oia oib oic oii oio oir oit oo- ooa oob ooc ooi ooo oor oot or- ora orb orc ori oro orr ort ot- ota otb otc oti oto otr ott ra- raa rab rac rai rao rar rat rba rbb rbc rbi rbo rbr rbt rca rcb rcc rci rco rcr rct ria rib ric rii rio rir rit roa rob roc roi roo ror rot rra rrb rrc rri rrr rrt rta rtb rtc rti rto rtr rtt taa tab tac tai tao tar tat tba tbb tbc tbi tbo tbr tbt tca tcb tcc tci tco tcr tct tia tib tic tii tio tir tit to- toa tob toc toi too tor tot tra trb trc tri tro trr trt tta ttb ttc tti tto ttr ttt