-ic bbb bbc bbi bbk bbr bbs bcb bcc bci bck bcr bcs bi- bib bic bii bik bir bis bkb bkc bkk bkr bks brb bri brk brr brs bsb bsc bsi bsk bsr bss c-- cbb cbc cbi cbk cbr cbs ccb ccc cci cck ccr ccs ci- cib cic cii cik cir cis ckb ckc cki cks crb crc cri crk crr crs csb csc csi csk csr css ibb ibc ibi ibk ibr ibs icb icc ici ick icr ics iib iic iii iir iis ikb ikc iki ikk ikr iks ir- irb irc iri irk irr irs is- isb isc isi isk isr iss kbb kbc kbi kbk kbr kbs kcb kcc kci kck kcr kcs kib kic kii kik kir kis kkb kkc kki kkk kkr kks krc kri krk krr krs ksb ksc ksi ksk ksr kss rbb rbc rbi rbk rbr rbs rcb rcc rci rcr rcs rib ric rii rik rir ris rkb rkc rkk rks rrb rrc rri rrk rrr rrs rsb rsc rsi rsk rsr rss sbb sbc sbi sbk sbr sbs scb scc sci sck scr scs sib sic sii sik sir sis sk- skb skc ski skk skr sks sr- srb src sri srk srr srs ss- ssb ssc ssi ssk ssr sss