-ol bbb bbi bbk bbl bbo bbr bbs bbt bi- bib bii bik bil bio bir bis bit bkb bkk bkl bko bkr bks bkt blb bli blk bll blo blr bls blt bob boi bok bol boo bor bos bot brb bri brk brl bro brr brs brt bsb bsi bsk bsl bso bsr bss bst btb bti btk btl bto btr bts btt ibb ibi ibk ibl ibo ibr ibs ibt iib iii iil iio iir iis iit ikb iki ikk ikl iko ikr iks ikt il- ilb ili ilk ill ilo ilr ils ilt io- iob ioi iol ioo ior ios iot ir- irb iri irk irl iro irr irs irt is- isb isi isk isl iso isr iss ist itb iti itk itl ito its itt k-t kbb kbi kbk kbl kbo kbr kbs kib kii kik kil kio kir kis kit kkb kki kkk kkl kkr kks kkt kl- klb kli klo klr kls klt kob koi kok kol koo kor kos kot kri krk krl kro krr krs krt ksb ksi ksk ksl kso ksr kss kst ktb ktk ktl kto ktr kts ktt lbb lbi lbk lbl lbo lbr lbs lbt lib lii lik lil lio lir lis lit lkb lkl lkr lks lkt llb lli llk lll llo llr lls llt lob loi lok lol loo lor los lot lrb lri lrk lro lrr lrs lrt lsb lsi lsk lsl lso lsr lss lst ltb lti ltk ltl lto ltr lts ltt o-i ob- obb obi obk obl obo obr obs obt oib oii oik oil oio oir ois oit okb oki okk okl oko okr oks olb oli olk oll olo ols olt oo- oob ooi ook ool ooo oor oos oot or- orb ori ork orl oro orr ors ort os- osb osi osk osl oso osr oss ost ot- otb oti otk otl oto otr ots ott rbb rbi rbk rbl rbo rbr rbs rbt rib rii rik ril rio rir ris rit rkb rkk rko rks rkt rli rll rlo rlr rls rlt rob roi rok rol roo ror ros rot rrb rri rrk rrl rrr rrs rrt rsb rsi rsk rsl rso rsr rss rst rtb rti rtk rtl rto rtr rts rtt sbb sbi sbk sbl sbo sbr sbs sbt sib sii sik sil sio sir sis sit sk- skb ski skk skl sko skr sks skt slb sli slk sll slo slr sls slt sob soi sok sol soo sor sos sot sr- srb sri srk srl sro srr srs srt ss- ssb ssi ssk ssl sso ssr sss sst stb sti stk stl sto str sts stt tbb tbi tbk tbl tbo tbr tbs tbt tib tii tik til tio tir tis tit tkb tkk tkl tko tkr tks tkt tli tlk tll tlo tlr tls tlt to- tob toi tok tol too tor tos tot trb tri trk trl tro trr trs trt tsb tsi tsk tsl tso tsr tss tst ttb tti ttk ttl tto ttr tts ttt