-er bbb bbc bbe bbk bbm bbo bbr bbt bcb bcc bce bck bcm bco bcr bct be- beb bec bee bek bem beo ber bet bkb bkc bke bkk bkm bko bkr bkt bmb bmc bme bmk bmm bmo bmr bmt bob boc boe bok bom boo bor bot brb bre brk brm bro brr brt btb btc bte btk btm bto btr btt c-- cbb cbc cbe cbk cbm cbo cbr cbt ccb ccc cce cck ccm cco ccr cct ce- ceb cec cee cek cem ceo cer cet ckb ckc ckm cko ckt cmb cmc cme cmk cmm cmo cmr cmt co- cob coc coe cok com coo cor cot crb crc cre crk crm cro crr crt ctb ctc cte ctk ctm cto ctr ctt ebb ebc ebe ebk ebm ebo ebr ebt ec- ecb ecc ece eck ecm eco ecr ect eeb eec eee eek eem eeo eer eet ekb ekc eke eko ekr ekt em- emb emc eme emk emm emo emr emt eo- eob eoc eoe eok eom eoo eor eot erb erc ere erk erm ero err ert etb etc ete etk etm eto etr ett k-t kbb kbc kbe kbk kbm kbo kbr kcb kcc kce kck kcm kcr kct ke- keb kec kee kek kem keo ker ket kkb kkc kke kkk kkm kkr kkt kmb kmc kme kmk kmm kmo kmt kob koc koe kok kom koo kor kot krc krk kro krr krt ktb ktc kte ktk ktm kto ktr ktt m-o m-r mbb mbc mbe mbk mbm mbo mbr mbt mc- mcb mcc mce mck mcm mco mcr mct meb mec mee mek mem meo mer met mkb mkc mke mkk mkm mko mkr mkt mmb mmc mme mmk mmm mmo mmr mmt mob moc moe mok mom moo mor mot mrb mrc mre mrk mrm mro mrr mrt mtb mtc mte mtk mtm mto mtr mtt ob- obb obc obe obk obm obo obr obt oc- ocb occ ock ocm oco ocr oct oeb oec oee oem oeo oer oet okb okc oke okk oko okr om- omb omc ome omm omo omr omt oo- oob ooc ook oom ooo oor oot or- orb orc ore ork orm oro orr ort ot- otb otc ote otk otm oto otr ott rbb rbc rbe rbk rbm rbo rbr rbt rcb rcc rce rcm rco rcr rct re- reb rec ree rek rem reo rer ret rkb rkc rke rkk rkm rko rkt rmb rmc rme rmm rmo rmr rmt rob roc roe rok rom roo ror rot rrb rrc rrk rrm rrr rrt rtb rtc rte rtk rtm rto rtr rtt tbb tbc tbe tbk tbm tbo tbr tbt tcb tcc tce tck tcm tco tcr tct te- teb tec tee tek tem teo ter tet tkb tkc tke tkk tkm tko tkr tkt tmb tmc tme tmk tmm tmo tmr tmt to- tob toc toe tok tom too tor tot trb trc tre trk trm tro trr trt ttb ttc tte ttk ttm tto ttr ttt