bbb bbe bbi bbo bbs bbt be- beb bee bei beo bes bet bi- bib bie bii bio bis bit bob boe boi boo bos bot bsb bse bsi bso bss bst btb bte bti bto bts btt ebb ebe ebi ebo ebs ebt eeb eee eeo ees eet eib eie eii eio eis eit eo- eob eoe eoi eoo eos eot es- esb ese esi eso ess est etb ete eti eto ets ett ibb ibe ibi ibo ibs ibt ie- iee iei ies iet iib iie iii iio iis iit io- iob ioe ioi ioo ios iot is- isb ise isi iso iss ist itb ite iti ito its itt o-i ob- obb obe obi obo obs obt oeb oee oei oeo oes oet oib oie oii oio ois oit oo- oob ooi ooo oos oot os- osb ose osi oso oss ost ot- otb ote oti oto ots ott sbb sbe sbi sbo sbs sbt se- seb see sei seo ses set sib sie sii sio sis sit sob soe soi soo sos sot ss- ssb sse ssi sso sss sst stb ste sti sto sts stt tbb tbe tbi tbo tbs tbt te- teb tee tei teo tes tet tib tie tii tio tis tit to- tob toe toi too tos tot tsb tse tsi tso tss tst ttb tte tti tto tts ttt