bbb bbc bbf bbk bbm bbo bbr bbt bcb bcc bcf bck bcm bco bcr bct bfb bfc bff bfm bfo bfr bft bkb bkc bkf bkk bkm bko bkr bkt bmb bmc bmf bmk bmm bmo bmr bmt bob boc bof bok bom boo bor bot brb brf brk brm bro brr brt btb btc btf btk btm bto btr btt c-- cbb cbc cbf cbk cbm cbo cbr cbt ccb ccc ccf cck ccm cco ccr cct cfb cfc cff cfk cfm cfo cfr cft ckb ckc ckm cko ckt cmb cmc cmf cmk cmm cmo cmr cmt co- cob coc cof cok com coo cor cot crb crc crf crk crm cro crr crt ctb ctc ctf ctk ctm cto ctr ctt fbb fbc fbf fbk fbm fbo fbr fbt fcb fcc fcf fck fcm fco fcr fct ffc fff ffk ffm ffo ffr fft fkb fkc fkf fkk fkm fkt fmb fmc fmf fmm fmo fmr fmt fob foc fof fok fom foo for fot frb frc frf frk frm fro frr frt ftb ftc ftf ftk ftm fto ftr ftt k-t kbb kbc kbf kbk kbm kbo kbr kcb kcc kck kcm kcr kct kfc kff kfm kfo kkb kkc kkk kkm kkr kkt kmb kmc kmf kmk kmm kmo kmt kob koc kof kok kom koo kor kot krc krf krk kro krr krt ktb ktc ktf ktk ktm kto ktr ktt m-f m-o m-r mbb mbc mbf mbk mbm mbo mbr mbt mc- mcb mcc mcf mck mcm mco mcr mct mfb mfc mff mfm mfo mfr mft mkb mkc mkk mkm mko mkr mkt mmb mmc mmf mmk mmm mmo mmr mmt mob moc mof mok mom moo mor mot mrb mrc mrf mrk mrm mro mrr mrt mtb mtc mtf mtk mtm mto mtr mtt ob- obb obc obf obk obm obo obr obt oc- ocb occ ocf ock ocm oco ocr oct of- ofb ofc off ofm ofo ofr oft okb okc okk oko okr om- omb omc omf omm omo omr omt oo- oob ooc oof ook oom ooo oor oot or- orb orc orf ork orm oro orr ort ot- otb otc otf otk otm oto otr ott rbb rbc rbf rbk rbm rbo rbr rbt rcb rcc rcf rcm rco rcr rct rfb rfc rff rfk rfm rfo rfr rft rkb rkc rkf rkk rkm rko rkt rmb rmc rmf rmm rmo rmr rmt rob roc rof rok rom roo ror rot rrb rrc rrf rrk rrm rrr rrt rtb rtc rtf rtk rtm rto rtr rtt tbb tbc tbf tbk tbm tbo tbr tbt tcb tcc tcf tck tcm tco tcr tct tfb tfc tff tfk tfm tfo tfr tft tkb tkc tkk tkm tko tkr tkt tmb tmc tmf tmk tmm tmo tmr tmt to- tob toc tof tok tom too tor tot trb trc trf trk trm tro trr trt ttb ttc ttf ttk ttm tto ttr ttt