-er bbb bbc bbe bbg bbk bbn bbo bbr bbs bbt bcb bcc bce bcg bck bcn bco bcr bcs bct be- beb bec bee beg bek ben beo ber bes bet bgb bgc bge bgg bgk bgn bgo bgr bgs bgt bkb bkc bke bkg bkk bkn bko bkr bks bkt bnb bnc bne bng bnk bnn bno bnr bns bnt bob boc boe bog bok bon boo bor bos bot brb bre brg brk brn bro brr brs brt bsb bsc bse bsg bsk bsn bso bsr bss bst btb btc bte btg btk btn bto btr bts btt c-- cbb cbc cbe cbg cbk cbn cbo cbr cbs cbt ccb ccc cce ccg cck ccn cco ccr ccs cct ce- ceb cec cee ceg cek cen ceo cer ces cet cgb cgc cge cgg cgn cgo cgr cgs cgt ckb ckc cko cks ckt cn- cnb cnc cne cng cnn cno cnr cns cnt co- cob coc coe cog cok con coo cor cos cot crb crc cre crg crk crn cro crr crs crt csb csc cse csg csk csn cso csr css cst ctb ctc cte ctg ctk ctn cto ctr cts ctt ebb ebc ebe ebg ebk ebn ebo ebr ebs ebt ec- ecb ecc ece ecg eck ecn eco ecr ecs ect eeb eec eee eeg eek een eeo eer ees eet egb egc ege egg egn ego egr egs egt ekb ekc eke ekg eko ekr eks ekt en- enb enc ene eng enk enn eno enr ens ent eo- eob eoc eoe eog eok eon eoo eor eos eot erb erc ere erg erk ern ero err ers ert es- esb esc ese esg esk esn eso esr ess est etb etc ete etg etk etn eto etr ets ett gbc gbe gbg gbk gbn gbo gbr gbs gbt gcb gcc gce gcg gck gcn gco gcr gcs gct ge- geb gec gee geg gek gen geo ger ges get ggb ggc ggg ggn ggo ggr ggs ggt gkb gkn gko gks gkt gnb gnc gne gnn gno gnr gns gnt gob goc goe gog gok gon goo gor gos got grb grc gre grg grk grn gro grr grs grt gsb gsc gse gsg gsk gsn gso gsr gss gst gtb gtc gte gtg gtk gtn gto gtr gts gtt k-t kbb kbc kbe kbk kbn kbo kbr kbs kcb kcc kce kcg kck kcn kcr kcs kct ke- keb kec kee keg kek ken keo ker kes ket kgb kgc kgo kgs kkb kkc kke kkk kkn kkr kks kkt kn- knc kne kng knk knn kno knr knt kob koc koe kog kok kon koo kor kos kot krc krg krk krn kro krr krs krt ksb ksc kse ksg ksk ksn kso ksr kss kst ktb ktc kte ktg ktk ktn kto ktr kts ktt nbb nbc nbe nbg nbk nbn nbo nbr nbs nbt ncb ncc nce ncg nck ncn nco ncr ncs nct ne- neb nec nee neg nek nen neo ner nes net ngb ngc nge ngg ngk ngn ngo ngs ngt nkc nke nkk nkn nko nkr nks nkt nnb nnc nne nng nnk nnn nno nns nnt no- nob noc noe nog nok non noo nor nos not nrb nrc nre nrg nrk nrn nro nrr nrs nrt nsb nsc nse nsg nsk nsn nso nsr nss nst ntb ntc nte ntg ntk ntn nto ntr nts ntt ob- obb obc obe obg obk obn obo obr obs obt oc- ocb occ ocg ock ocn oco ocr ocs oct oeb oec oee oeg oen oeo oer oes oet ogc oge ogg ogn ogo ogs ogt okb okc oke okg okk oko okr oks on- onb onc one ong onk onn ono onr ons ont oo- oob ooc oog ook oon ooo oor oos oot or- orb orc ore org ork orn oro orr ors ort os- osb osc ose osg osk osn oso osr oss ost ot- otb otc ote otg otk otn oto otr ots ott rbb rbc rbe rbg rbk rbn rbo rbr rbs rbt rcb rcc rce rcg rcn rco rcr rcs rct re- reb rec ree reg rek ren reo rer res ret rgb rgc rge rgg rgk rgn rgo rgr rgs rgt rkb rkc rke rkg rkk rko rks rkt rnb rnc rng rnn rno rnr rns rnt rob roc roe rog rok ron roo ror ros rot rrb rrc rrg rrk rrn rrr rrs rrt rsb rsc rse rsg rsk rsn rso rsr rss rst rtb rtc rte rtg rtk rtn rto rtr rts rtt sbb sbc sbe sbg sbk sbn sbo sbr sbs sbt scb scc sce scg sck scn sco scr scs sct se- seb sec see seg sek sen seo ser ses set sgb sgc sge sgg sgk sgn sgo sgr sgs sgt sk- skb skc ske skg skk sko skr sks skt snb snc sne sng snk snn sno snr sns snt sob soc soe sog sok son soo sor sos sot sr- srb src sre srg srk srn sro srr srs srt ss- ssb ssc sse ssg ssk ssn sso ssr sss sst stb stc ste stg stk stn sto str sts stt tbb tbc tbe tbg tbk tbn tbo tbr tbs tbt tcb tcc tce tcg tck tcn tco tcr tcs tct te- teb tec tee teg tek ten teo ter tes tet tgb tgc tge tgg tgk tgn tgo tgr tgs tgt tkb tkc tke tkg tkk tko tkr tks tkt tnb tnc tne tng tnk tnn tno tnr tns tnt to- tob toc toe tog tok ton too tor tos tot trb trc tre trg trk trn tro trr trs trt tsb tsc tse tsg tsk tsn tso tsr tss tst ttb ttc tte ttg ttk ttn tto ttr tts ttt