-ic a-a a-b a-c a-i a-t aaa aab aac aai aan aar aat ab- aba abb abc abi abn abr abt ac- aca acb acc aci acn acr act ai- aia aib aic aii ain air ait an- ana anb anc ani ann anr ant ar- ara arb arc ari arn arr art at- ata atb atc ati atn atr att baa bab bac bai ban bar bat bba bbb bbc bbi bbn bbr bbt bca bcb bcc bci bcn bcr bct bi- bia bib bic bii bin bir bit bna bnb bnc bni bnn bnr bnt bra brb bri brn brr brt bta btb btc bti btn btr btt c-- caa cab cac cai can car cat cba cbb cbc cbi cbn cbr cbt cca ccb ccc cci ccn ccr cct ci- cia cib cic cii cin cir cit cn- cna cnb cnc cni cnn cnr cnt cra crb crc cri crn crr crt cta ctb ctc cti ctn ctr ctt ia- iaa iab iac iai ian iar iat iba ibb ibc ibi ibn ibr ibt ica icb icc ici icn icr ict iia iib iic iii iin iir iit in- ina inb inc ini inn inr int ir- ira irb irc iri irn irr irt ita itb itc iti itn itt n-i naa nab nac nai nan nar nat nba nbb nbc nbi nbn nbr nbt nca ncb ncc nci ncn ncr nct nia nib nic nii nin nir nit nna nnb nnc nni nnn nnt nra nrb nrc nri nrn nrr nrt nta ntb ntc nti ntn ntr ntt ra- raa rab rac rai ran rar rat rba rbb rbc rbi rbn rbr rbt rca rcb rcc rci rcn rcr rct ria rib ric rii rin rir rit rna rnb rnc rni rnn rnr rnt rra rrb rrc rri rrn rrr rrt rta rtb rtc rti rtn rtr rtt taa tab tac tai tan tar tat tba tbb tbc tbi tbn tbr tbt tca tcb tcc tci tcn tcr tct tia tib tic tii tin tir tit tna tnb tnc tni tnn tnr tnt tra trb trc tri trn trr trt tta ttb ttc tti ttn ttr ttt