-ic a-a a-b a-c a-i a-t aaa aab aac aai aar aat ab- aba abb abc abi abr abt ac- aca acb acc aci acr act ai- aia aib aic aii air ait ar- ara arb arc ari arr art at- ata atb atc ati atr att baa bab bac bai bar bat bba bbb bbc bbi bbr bbt bca bcb bcc bci bcr bct bi- bia bib bic bii bir bit bra brb bri brr brt bta btb btc bti btr btt c-- caa cab cac cai car cat cba cbb cbc cbi cbr cbt cca ccb ccc cci ccr cct ci- cia cib cic cii cir cit cra crb crc cri crr crt cta ctb ctc cti ctr ctt ia- iaa iab iac iai iar iat iba ibb ibc ibi ibr ibt ica icb icc ici icr ict iia iib iic iii iir iit ir- ira irb irc iri irr irt ita itb itc iti itt ra- raa rab rac rai rar rat rba rbb rbc rbi rbr rbt rca rcb rcc rci rcr rct ria rib ric rii rir rit rra rrb rrc rri rrr rrt rta rtb rtc rti rtr rtt taa tab tac tai tar tat tba tbb tbc tbi tbr tbt tca tcb tcc tci tcr tct tia tib tic tii tir tit tra trb trc tri trr trt tta ttb ttc tti ttr ttt