-ic a-a a-b a-c a-i aaa aab aac aai aan aar ab- aba abb abc abi abn abr ac- aca acb acc aci acn acr ai- aia aib aic aii ain air an- ana anb anc ani ann anr ar- ara arb arc ari arn arr baa bab bac bai ban bar bba bbb bbc bbi bbn bbr bca bcb bcc bci bcn bcr bi- bia bib bic bii bin bir bna bnb bnc bni bnn bnr bra brb bri brn brr c-- caa cab cac cai can car cba cbb cbc cbi cbn cbr cca ccb ccc cci ccn ccr ci- cia cib cic cii cin cir cn- cna cnb cnc cni cnn cnr cra crb crc cri crn crr ia- iaa iab iac iai ian iar iba ibb ibc ibi ibn ibr ica icb icc ici icn icr iia iib iic iii iin iir in- ina inb inc ini inn inr ir- ira irb irc iri irn irr n-i naa nab nac nai nan nar nba nbb nbc nbi nbn nbr nca ncb ncc nci ncn ncr nia nib nic nii nin nir nna nnb nnc nni nnn nra nrb nrc nri nrn nrr ra- raa rab rac rai ran rar rba rbb rbc rbi rbn rbr rca rcb rcc rci rcn rcr ria rib ric rii rin rir rna rnb rnc rni rnn rnr rra rrb rrc rri rrn rrr