-ic b-u bbb bbc bbi bbs bbt bbu bcb bcc bci bcs bct bcu bi- bib bic bii bis bit biu bsb bsc bsi bss bst bsu btb btc bti bts btt btu bub buc bui bus but buu c-- cbb cbc cbi cbs cbt cbu ccb ccc cci ccs cct ccu ci- cib cic cii cis cit ciu csb csc csi css cst csu ctb ctc cti cts ctt ctu cub cuc cui cus cut cuu ibb ibc ibi ibs ibt ibu icb icc ici ics ict icu iib iic iii iis iit iiu is- isb isc isi iss ist isu itb itc iti its itt itu iu- iub iuc iui ius iut sbb sbc sbi sbs sbt sbu 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 sub suc sui sus sut suu tbb tbc tbi tbs tbt tbu tcb tcc tci tcs tct tcu tib tic tii tis tit tiu tsb tsc tsi tss tst tsu ttb ttc tti tts ttt ttu tub tuc tui tus tut tuu ubb ubc ubi ubs ubt ubu ucb ucc uci ucs uct ucu uib uic uii uis uit uiu usb usc usi uss ust usu utb utc uti uts utt utu uuc uus uut uuu