-ic a-a a-b a-c a-i aaa aab aac aai aar aas ab- aba abb abc abi abr abs ac- aca acb acc aci acr acs ai- aia aib aic aii air ais ar- ara arb arc ari arr ars as- asa asb asc asi asr ass baa bab bac bai bar bas bba bbb bbc bbi bbr bbs bca bcb bcc bci bcr bcs bi- bia bib bic bii bir bis bra brb bri brr brs bsa bsb bsc bsi bsr bss c-- caa cab cac cai car cas cba cbb cbc cbi cbr cbs cca ccb ccc cci ccr ccs ci- cia cib cic cii cir cis cra crb crc cri crr crs csa csb csc csi csr css ia- iaa iab iac iai iar ias iba ibb ibc ibi ibr ibs ica icb icc ici icr ics iia iib iic iii iir iis ir- ira irb irc iri irr irs is- isa isb isc isi isr iss ra- raa rab rac rai rar ras rba rbb rbc rbi rbr rbs rca rcb rcc rci rcr rcs ria rib ric rii rir ris rra rrb rrc rri rrr rrs rsa rsb rsc rsi rsr rss saa sab sac sai sar sas sba sbb sbc sbi sbr sbs sca scb scc sci scr scs sia sib sic sii sir sis sr- sra srb src sri srr srs ss- ssa ssb ssc ssi ssr sss