-er bbb bbe bbf bbi bbk bbo bbr bbs bbt be- beb bee bef bei bek beo ber bes bet bfb bfe bff bfi bfo bfr bfs bft bi- bib bie bif bii bik bio bir bis bit bkb bke bkf bkk bko bkr bks bkt bob boe bof boi bok boo bor bos bot brb bre brf bri brk bro brr brs brt bsb bse bsf bsi bsk bso bsr bss bst btb bte btf bti btk bto btr bts btt ebb ebe ebf ebi ebk ebo ebr ebs ebt eeb eee eef eek eeo eer ees eet ef- efb efe eff efi efo efr efs eft eib eie eif eii eik eio eir eis eit ekb eke ekf eki eko ekr eks ekt eo- eob eoe eof eoi eok eoo eor eos eot erb ere erf eri erk ero err ers ert es- esb ese esf esi esk eso esr ess est etb ete etf eti etk eto etr ets ett fbb fbe fbf fbi fbk fbo fbr fbs fbt feb fee fef fei fek feo fer fes fet ffe fff ffi ffk ffo ffr ffs fft fib fie fif fii fik fir fis fit fkb fkf fki fkk fkt fob foe fof foi fok foo for fos fot frb fre frf fri frk fro frr frs frt fsb fse fsf fsi fsk fso fsr fss fst ftb fte ftf fti ftk fto ftr fts ftt i-f ibb ibe ibf ibi ibk ibo ibr ibs ibt ie- iee ief iei iek ier ies iet ifb ife iff ifi ifo ifr ifs ift iib iie iif iii iio iir iis iit ikb ike ikf iki ikk iko ikr iks ikt io- iob ioe iof ioi ioo ior ios iot ir- irb ire irf iri irk iro irr irs irt is- isb ise isf isi isk iso isr iss ist itb ite itf iti itk ito its itt k-t kbb kbe kbf kbi kbk kbo kbr kbs ke- keb kee kef kei kek keo ker kes ket kff kfi kfo kfs kib kie kif kii kik kio kir kis kit kkb kke kki kkk kkr kks kkt kob koe kof koi kok koo kor kos kot krf kri krk kro krr krs krt ksb kse ksf ksi ksk kso ksr kss kst ktb kte ktf ktk kto ktr kts ktt o-i ob- obb obe obf obi obk obo obr obs obt oeb oee oef oei oeo oer oes oet of- ofb ofe off ofi ofo ofr ofs oft oib oie oif oii oik oio oir ois oit okb oke oki okk oko okr oks oo- oob oof ooi ook ooo oor oos oot or- orb ore orf ori ork oro orr ors ort os- osb ose osf osi osk oso osr oss ost ot- otb ote otf oti otk oto otr ots ott rbb rbe rbf rbi rbk rbo rbr rbs rbt re- reb ree ref rei rek reo rer res ret rfb rfe rff rfi rfk rfo rfr rfs rft rib rie rif rii rik rio rir ris rit rkb rke rkf rkk rko rks rkt rob roe rof roi rok roo ror ros rot rrb rrf rri rrk rrr rrs rrt rsb rse rsf rsi rsk rso rsr rss rst rtb rte rtf rti rtk rto rtr rts rtt sbb sbe sbf sbi sbk sbo sbr sbs sbt se- seb see sef sei sek seo ser ses set sfb sfe sff sfi sfk sfo sfr sfs sft sib sie sif sii sik sio sir sis sit sk- skb ske skf ski skk sko skr sks skt sob soe sof soi sok soo sor sos sot sr- srb sre srf sri srk sro srr srs srt ss- ssb sse ssf ssi ssk sso ssr sss sst stb ste stf sti stk sto str sts stt tbb tbe tbf tbi tbk tbo tbr tbs tbt te- teb tee tef tei tek teo ter tes tet tfb tfe tff tfi tfk tfo tfr tfs tft tib tie tif tii tik tio tir tis tit tkb tke tkk tko tkr tks tkt to- tob toe tof toi tok too tor tos tot trb tre trf tri trk tro trr trs trt tsb tse tsf tsi tsk tso tsr tss tst ttb tte ttf tti ttk tto ttr tts ttt