-er bbb bbe bbg bbk bbo bbr bbs bbt be- beb bee beg bek beo ber bes bet bgb bge bgg bgk bgo bgr bgs bgt bkb bke bkg bkk bko bkr bks bkt bob boe bog bok boo bor bos bot brb bre brg brk bro brr brs brt bsb bse bsg bsk bso bsr bss bst btb bte btg btk bto btr bts btt ebb ebe ebg ebk ebo ebr ebs ebt eeb eee eeg eek eeo eer ees eet egb ege egg ego egr egs egt ekb eke ekg eko ekr eks ekt eo- eob eoe eog eok eoo eor eos eot erb ere erg erk ero err ers ert es- esb ese esg esk eso esr ess est etb ete etg etk eto etr ets ett gbe gbg gbk gbo gbr gbs gbt ge- geb gee geg gek geo ger ges get ggb ggg ggo ggr ggs ggt gkb gko gks gkt gob goe gog gok goo gor gos got grb gre grg grk gro grr grs grt gsb gse gsg gsk gso gsr gss gst gtb gte gtg gtk gto gtr gts gtt k-t kbb kbe kbk kbo kbr kbs ke- keb kee keg kek keo ker kes ket kgb kgo kgs kkb kke kkk kkr kks kkt kob koe kog kok koo kor kos kot krg krk kro krr krs krt ksb kse ksg ksk kso ksr kss kst ktb kte ktg ktk kto ktr kts ktt ob- obb obe obg obk obo obr obs obt oeb oee oeg oeo oer oes oet oge ogg ogo ogs ogt okb oke okg okk oko okr oks oo- oob oog ook ooo oor oos oot or- orb ore org ork oro orr ors ort os- osb ose osg osk oso osr oss ost ot- otb ote otg otk oto otr ots ott rbb rbe rbg rbk rbo rbr rbs rbt re- reb ree reg rek reo rer res ret rgb rge rgg rgk rgo rgr rgs rgt rkb rke rkg rkk rko rks rkt rob roe rog rok roo ror ros rot rrb rrg rrk rrr rrs rrt rsb rse rsg rsk rso rsr rss rst rtb rte rtg rtk rto rtr rts rtt sbb sbe sbg sbk sbo sbr sbs sbt se- seb see seg sek seo ser ses set sgb sge sgg sgk sgo sgr sgs sgt sk- skb ske skg skk sko skr sks skt sob soe sog sok soo sor sos sot sr- srb sre srg srk sro srr srs srt ss- ssb sse ssg ssk sso ssr sss sst stb ste stg stk sto str sts stt tbb tbe tbg tbk tbo tbr tbs tbt te- teb tee teg tek teo ter tes tet tgb tge tgg tgk tgo tgr tgs tgt tkb tke tkg tkk tko tkr tks tkt to- tob toe tog tok too tor tos tot trb tre trg trk tro trr trs trt tsb tse tsg tsk tso tsr tss tst ttb tte ttg ttk tto ttr tts ttt