-ic bbb bbc bbi bbr bbs bcb bcc bci bcr bcs bi- bib bic bii bir bis brb bri brr brs bsb bsc bsi bsr bss c-- cbb cbc cbi cbr cbs ccb ccc cci ccr ccs ci- cib cic cii cir cis crb crc cri crr crs csb csc csi csr css ibb ibc ibi ibr ibs icb icc ici icr ics iib iic iii iir iis ir- irb irc iri irr irs is- isb isc isi isr iss rbb rbc rbi rbr rbs rcb rcc rci rcr rcs rib ric rii rir ris rrb rrc rri rrr rrs rsb rsc rsi rsr rss sbb sbc sbi sbr sbs scb scc sci scr scs sib sic sii sir sis sr- srb src sri srr srs ss- ssb ssc ssi ssr sss