bbb bbe bbi bbs bbt bbx be- beb bee bei bes bet bex bi- bib bie bii bis bit bix bsb bse bsi bss bst bsx btb bte bti bts btt btx bxb bxi bxx ebb ebe ebi ebs ebt ebx eeb eee ees eet eex eib eie eii eis eit eix es- esb ese esi ess est esx etb ete eti ets ett etx ex- exe exi exs ext exx ibb ibe ibi ibs ibt ibx ie- iee iei ies iet iex iib iie iii iis iit iix is- isb ise isi iss ist itb ite iti its itt itx ixe ixi sbb sbe sbi sbs sbt sbx se- seb see sei ses set sex sib sie sii sis sit six ss- ssb sse ssi sss sst ssx stb ste sti sts stt stx sxi sxs sxt t-x tbb tbe tbi tbs tbt te- teb tee tei tes tet tex tib tie tii tis tit tix tsb tse tsi tss tst tsx ttb tte tti tts ttt ttx txe txi txs txt xbe xbx xee xes xet xex xie xii xis xit xix xsb xsi xss xst xti xts xtx xxi xxx