-ic bbb bbc bbi bbs bbt bcb bcc bci bcs bct bi- bib bic bii bis bit bsb bsc bsi bss bst btb btc bti bts btt c-- cbb cbc cbi cbs cbt ccb ccc cci ccs cct ci- cib cic cii cis cit csb csc csi css cst ctb ctc cti cts ctt ibb ibc ibi ibs ibt icb icc ici ics ict iib iic iii iis iit is- isb isc isi iss ist itb itc iti its itt sbb sbc sbi sbs sbt scb scc sci scs sct sib sic sii sis sit ss- ssb ssc ssi sss sst stb stc sti sts stt tbb tbc tbi tbs tbt tcb tcc tci tcs tct tib tic tii tis tit tsb tsc tsi tss tst ttb ttc tti tts ttt