b-u bbb bbc bbg bbk bbr bbt bbu bcb bcc bcg bck bcr bct bcu bgb bgc bgg bgk bgr bgt bgu bkb bkc bkg bkk bkr bkt brb brg brk brr brt bru btb btc btg btk btr btt btu bub buc bug buk bur but buu c-- cbb cbc cbg cbk cbr cbt cbu ccb ccc ccg cck ccr cct ccu cgb cgc cgg cgr cgt cgu ckb ckc ckt crb crc crg crk crr crt cru ctb ctc ctg ctk ctr ctt ctu cub cuc cug cuk cur cut cuu gbc gbg gbk gbr gbt gbu gcb gcc gcg gck gcr gct gcu ggb ggc ggg ggr ggt ggu gkb gkt grb grc grg grk grr grt gru gtb gtc gtg gtk gtr gtt gtu gu- gub guc gug guk gur gut guu k-t kbb kbc kbk kbr kbu kcb kcc kcg kck kcr kct kcu kgb kgc kgu kkb kkc kkk kkr kkt kku krc krg krk krr krt kru ktb ktc ktg ktk ktr ktt ktu kub kuc kug kuk kur kut kuu rbb rbc rbg rbk rbr rbt rbu rcb rcc rcg rcr rct rcu rgb rgc rgg rgk rgr rgt rkb rkc rkg rkk rkt rku rrb rrc rrg rrk rrr rrt rru rtb rtc rtg rtk rtr rtt rtu rub ruc rug ruk rur rut ruu tbb tbc tbg tbk tbr tbt tbu tcb tcc tcg tck tcr tct tcu tgb tgc tgg tgk tgr tgt tgu tkb tkc tkg tkk tkr tkt trb trc trg trk trr trt tru ttb ttc ttg ttk ttr ttt ttu tub tuc tug tuk tur tut tuu ubb ubc ubg ubk ubr ubt ubu ucb ucc ucg uck ucr uct ucu ugb ugc ugg ugk ugr ugt ugu ukb ukc ukk ukr uku ur- urb urc urg urk urr urt uru utb utc utk utr utt utu uuc uug uur uut uuu