-ic b-u bbb bbc bbi bbs bbt bbu bby bcb bcc bci bcs bct bcu bcy bi- bib bic bii bis bit biu biy bsb bsc bsi bss bst bsu bsy btb btc bti bts btt btu bty bub buc bui bus but buu buy by- byc byi bys byt byu c-- cbb cbc cbi cbs cbt cbu cby ccb ccc cci ccs cct ccu ci- cib cic cii cis cit ciu csb csc csi css cst csu csy ctb ctc cti cts ctt ctu cty cub cuc cui cus cut cuu cuy cyb cyc cys cyt ibb ibc ibi ibs ibt ibu iby icb icc ici ics ict icu icy iib iic iii iis iit iiu is- isb isc isi iss ist isu isy itb itc iti its itt itu ity iu- iub iuc iui ius iut iyc iys iyt iyy sbb sbc sbi sbs sbt sbu sby scb scc sci scs sct scu sib sic sii sis sit siu ss- ssb ssc ssi sss sst ssu stb stc sti sts stt stu sty sub suc sui sus sut suu suy sy- syb syc syi sys syt syu tbb tbc tbi tbs tbt tbu tcb tcc tci tcs tct tcu tib tic tii tis tit tiu tiy tsb tsc tsi tss tst tsu tsy ttb ttc tti tts ttt ttu tty tub tuc tui tus tut tuu tuy tyc tys tyt ubb ubc ubi ubs ubt ubu uby ucb ucc uci ucs uct ucu uib uic uii uis uit uiu usb usc usi uss ust usu utb utc uti uts utt utu uty uuc uus uut uuu uyc uyi uys uyu ybc ybi ybs yby ycc yci ycs ycu ycy yii yis yit ysb ysc ysi yss yst ysu ysy ytc yts ytt ytu yui yus yut yuu yuy yyb yyc yys yyt yyu yyy