-ol bbb bbe bbk bbl bbo bbs bbt be- beb bee bek bel beo bes bet bkb bke bkk bkl bko bks bkt blb ble blk bll blo bls blt bob boe bok bol boo bos bot bsb bse bsk bsl bso bss bst btb bte btk btl bto bts btt ebb ebe ebk ebl ebo ebs ebt eeb eee eek eel eeo ees eet ekb eke ekl eko eks ekt elb ele elk ell elo els elt eo- eob eoe eok eol eoo eos eot es- esb ese esk esl eso ess est etb ete etk etl eto ets ett k-t kbb kbe kbk kbl kbo kbs ke- keb kee kek kel keo kes ket kkb kke kkk kkl kks kkt kl- klb klo kls klt kob koe kok kol koo kos kot ksb kse ksk ksl kso kss kst ktb kte ktk ktl kto kts ktt lbb lbe lbk lbl lbo lbs lbt leb lee lek lel leo les let lkb lkl lks lkt llb lle llk lll llo lls llt lob loe lok lol loo los lot lsb lse lsk lsl lso lss lst ltb lte ltk ltl lto lts ltt ob- obb obe obk obl obo obs obt oeb oee oel oeo oes oet okb oke okk okl oko oks olb ole olk oll olo ols olt oo- oob ook ool ooo oos oot os- osb ose osk osl oso oss ost ot- otb ote otk otl oto ots ott sbb sbe sbk sbl sbo sbs sbt se- seb see sek sel seo ses set sk- skb ske skk skl sko sks skt slb sle slk sll slo sls slt sob soe sok sol soo sos sot ss- ssb sse ssk ssl sso sss sst stb ste stk stl sto sts stt tbb tbe tbk tbl tbo tbs tbt te- teb tee tek tel teo tes tet tkb tke tkk tkl tko tks tkt tle tlk tll tlo tls tlt to- tob toe tok tol too tos tot tsb tse tsk tsl tso tss tst ttb tte ttk ttl tto tts ttt