-er bbb bbe bbn bbo bbr bbs bbt be- beb bee ben beo ber bes bet bnb bne bnn bno bnr bns bnt bob boe bon boo bor bos bot brb bre brn bro brr brs brt bsb bse bsn bso bsr bss bst btb bte btn bto btr bts btt ebb ebe ebn ebo ebr ebs ebt eeb eee een eeo eer ees eet en- enb ene enn eno enr ens ent eo- eob eoe eon eoo eor eos eot erb ere ern ero err ers ert es- esb ese esn eso esr ess est etb ete etn eto etr ets ett nbb nbe nbn nbo nbr nbs nbt ne- neb nee nen neo ner nes net nnb nne nnn nno nns nnt no- nob noe non noo nor nos not nrb nre nrn nro nrr nrs nrt nsb nse nsn nso nsr nss nst ntb nte ntn nto ntr nts ntt ob- obb obe obn obo obr obs obt oeb oee oen oeo oer oes oet on- onb one onn ono onr ons ont oo- oob oon ooo oor oos oot or- orb ore orn oro orr ors ort os- osb ose osn oso osr oss ost ot- otb ote otn oto otr ots ott rbb rbe rbn rbo rbr rbs rbt re- reb ree ren reo rer res ret rnb rnn rno rnr rns rnt rob roe ron roo ror ros rot rrb rrn rrr rrs rrt rsb rse rsn rso rsr rss rst rtb rte rtn rto rtr rts rtt sbb sbe sbn sbo sbr sbs sbt se- seb see sen seo ser ses set snb sne snn sno snr sns snt sob soe son soo sor sos sot sr- srb sre srn sro srr srs srt ss- ssb sse ssn sso ssr sss sst stb ste stn sto str sts stt tbb tbe tbn tbo tbr tbs tbt te- teb tee ten teo ter tes tet tnb tne tnn tno tnr tns tnt to- tob toe ton too tor tos tot trb tre trn tro trr trs trt tsb tse tsn tso tsr tss tst ttb tte ttn tto ttr tts ttt