bbb bbe bbi bbk bbo bbs bbt be- beb bee bei bek beo bes bet bi- bib bie bii bik bio bis bit bkb bke bkk bko bks bkt bob boe boi bok boo bos bot bsb bse bsi bsk bso bss bst btb bte bti btk bto bts btt ebb ebe ebi ebk ebo ebs ebt eeb eee eek eeo ees eet eib eie eii eik eio eis eit ekb eke eki eko eks ekt eo- eob eoe eoi eok eoo eos eot es- esb ese esi esk eso ess est etb ete eti etk eto ets ett ibb ibe ibi ibk ibo ibs ibt ie- iee iei iek ies iet iib iie iii iio iis iit ikb ike iki ikk iko iks ikt io- iob ioe ioi ioo ios iot is- isb ise isi isk iso iss ist itb ite iti itk ito its itt k-t kbb kbe kbi kbk kbo kbs ke- keb kee kei kek keo kes ket kib kie kii kik kio kis kit kkb kke kki kkk kks kkt kob koe koi kok koo kos kot ksb kse ksi ksk kso kss kst ktb kte ktk kto kts ktt o-i ob- obb obe obi obk obo obs obt oeb oee oei oeo oes oet oib oie oii oik oio ois oit okb oke oki okk oko oks oo- oob ooi ook ooo oos oot os- osb ose osi osk oso oss ost ot- otb ote oti otk oto ots ott sbb sbe sbi sbk sbo sbs sbt se- seb see sei sek seo ses set sib sie sii sik sio sis sit sk- skb ske ski skk sko sks skt sob soe soi sok soo sos sot ss- ssb sse ssi ssk sso sss sst stb ste sti stk sto sts stt tbb tbe tbi tbk tbo tbs tbt te- teb tee tei tek teo tes tet tib tie tii tik tio tis tit tkb tke tkk tko tks tkt to- tob toe toi tok too tos tot tsb tse tsi tsk tso tss tst ttb tte tti ttk tto tts ttt