-er bbb bbc bbe bbg bbk bbl bbr bbs bbt bcb bcc bce bcg bck bcl bcr bcs bct be- beb bec bee beg bek bel ber bes bet bgb bgc bge bgg bgk bgl bgr bgs bgt bkb bkc bke bkg bkk bkl bkr bks bkt blb blc ble blg blk bll blr bls blt brb bre brg brk brl brr brs brt bsb bsc bse bsg bsk bsl bsr bss bst btb btc bte btg btk btl btr bts btt c-- cbb cbc cbe cbg cbk cbl cbr cbs cbt ccb ccc cce ccg cck ccl ccr ccs cct ce- ceb cec cee ceg cek cel cer ces cet cgb cgc cge cgg cgl cgr cgs cgt ckb ckc cks ckt cl- clb clc cle clg clk cll clr cls clt crb crc cre crg crk crl crr crs crt csb csc cse csg csk csl csr css cst ctb ctc cte ctg ctk ctl ctr cts ctt ebb ebc ebe ebg ebk ebl ebr ebs ebt ec- ecb ecc ece ecg eck ecl ecr ecs ect eeb eec eee eeg eek eel eer ees eet egb egc ege egg egl egr egs egt ekb ekc eke ekg ekl ekr eks ekt elb elc ele elg elk ell elr els elt erb erc ere erg erk erl err ers ert es- esb esc ese esg esk esl esr ess est etb etc ete etg etk etl etr ets ett gbc gbe gbg gbk gbl gbr gbs gbt gcb gcc gce gcg gck gcl gcr gcs gct ge- geb gec gee geg gek gel ger ges get ggb ggc ggg ggr ggs ggt gkb gks gkt glb glc gle glg glk gll glr gls glt grb grc gre grg grk grl grr grs grt gsb gsc gse gsg gsk gsl gsr gss gst gtb gtc gte gtg gtk gtl gtr gts gtt k-t kbb kbc kbe kbk kbl kbr kbs kcb kcc kce kcg kck kcl kcr kcs kct ke- keb kec kee keg kek kel ker kes ket kgb kgc kgl kgs kkb kkc kke kkk kkl kkr kks kkt kl- klb klc klg klr kls klt krc krg krk krl krr krs krt ksb ksc kse ksg ksk ksl ksr kss kst ktb ktc kte ktg ktk ktl ktr kts ktt lbb lbc lbe lbg lbk lbl lbr lbs lbt lcb lcc lce lcg lck lcl lcr lcs lct leb lec lee leg lek lel ler les let lgb lgc lge lgg lgk lgl lgr lgs lgt lkb lkg lkl lkr lks lkt llb llc lle llg llk lll llr lls llt lrb lrc lrg lrk lrr lrs lrt lsb lsc lse lsg lsk lsl lsr lss lst ltb ltc lte ltg ltk ltl ltr lts ltt rbb rbc rbe rbg rbk rbl rbr rbs rbt rcb rcc rce rcg rcl rcr rcs rct re- reb rec ree reg rek rel rer res ret rgb rgc rge rgg rgk rgr rgs rgt rkb rkc rke rkg rkk rks rkt rlc rle rlg rll rlr rls rlt rrb rrc rrg rrk rrl rrr rrs rrt rsb rsc rse rsg rsk rsl rsr rss rst rtb rtc rte rtg rtk rtl rtr rts rtt sbb sbc sbe sbg sbk sbl sbr sbs sbt scb scc sce scg sck scl scr scs sct se- seb sec see seg sek sel ser ses set sgb sgc sge sgg sgk sgl sgr sgs sgt sk- skb skc ske skg skk skl skr sks skt slb slc sle slg slk sll slr sls slt sr- srb src sre srg srk srl srr srs srt ss- ssb ssc sse ssg ssk ssl ssr sss sst stb stc ste stg stk stl str sts stt tbb tbc tbe tbg tbk tbl tbr tbs tbt tcb tcc tce tcg tck tcl tcr tcs tct te- teb tec tee teg tek tel ter tes tet tgb tgc tge tgg tgk tgl tgr tgs tgt tkb tkc tke tkg tkk tkl tkr tks tkt tlc tle tlg tlk tll tlr tls tlt trb trc tre trg trk trl trr trs trt tsb tsc tse tsg tsk tsl tsr tss tst ttb ttc tte ttg ttk ttl ttr tts ttt