-ic b-u bbb bbc bbi bbr bbs bbt bbu bcb bcc bci bcr bcs bct bcu bi- bib bic bii bir bis bit biu brb bri brr brs brt bru bsb bsc bsi bsr bss bst bsu btb btc bti btr bts btt btu bub buc bui bur bus but buu c-- cbb cbc cbi cbr cbs cbt cbu ccb ccc cci ccr ccs cct ccu ci- cib cic cii cir cis cit ciu crb crc cri crr crs crt cru csb csc csi csr css cst csu ctb ctc cti ctr cts ctt ctu cub cuc cui cur cus cut cuu ibb ibc ibi ibr ibs ibt ibu icb icc ici icr ics ict icu iib iic iii iir iis iit iiu ir- irb irc iri irr irs irt iru is- isb isc isi isr iss ist isu itb itc iti its itt itu iu- iub iuc iui iur ius iut rbb rbc rbi rbr rbs rbt rbu rcb rcc rci rcr rcs rct rcu rib ric rii rir ris rit rrb rrc rri rrr rrs rrt rru rsb rsc rsi rsr rss rst rsu rtb rtc rti rtr rts rtt rtu rub ruc rui rur rus rut ruu sbb sbc sbi sbr sbs sbt sbu scb scc sci scr scs sct scu sib sic sii sir sis sit siu sr- srb src sri srr srs srt ss- ssb ssc ssi ssr sss sst ssu stb stc sti str sts stt stu sub suc sui sur sus sut suu tbb tbc tbi tbr tbs tbt tbu tcb tcc tci tcr tcs tct tcu tib tic tii tir tis tit tiu trb trc tri trr trs trt tru tsb tsc tsi tsr tss tst tsu ttb ttc tti ttr tts ttt ttu tub tuc tui tur tus tut tuu ubb ubc ubi ubr ubs ubt ubu ucb ucc uci ucr ucs uct ucu uib uic uii uir uis uit uiu ur- urb urc uri urr urs urt uru usb usc usi usr uss ust usu utb utc uti utr uts utt utu uuc uur uus uut uuu