-er b-u bbb bbc bbe bbf bbg bbk bbr bbu bcb bcc bce bcf bcg bck bcr bcu be- beb bec bee bef beg bek ber beu bfb bfc bfe bff bfg bfr bfu bgb bgc bge bgf bgg bgk bgr bgu bkb bkc bke bkf bkg bkk bkr brb bre brf brg brk brr bru bub buc bue buf bug buk bur buu c-- cbb cbc cbe cbf cbg cbk cbr cbu ccb ccc cce ccf ccg cck ccr ccu ce- ceb cec cee cef ceg cek cer ceu cfb cfc cfe cff cfg cfk cfr cfu cgb cgc cge cgg cgr cgu ckb ckc crb crc cre crf crg crk crr cru cub cuc cue cuf cug cuk cur cuu ebb ebc ebe ebf ebg ebk ebr ebu ec- ecb ecc ece ecf ecg eck ecr ecu eeb eec eee eef eeg eek eer ef- efb efc efe eff efg efr egb egc ege egf egg egr egu ekb ekc eke ekf ekg ekr eku erb erc ere erf erg erk err eru eu- eub euc eue euf eug eur fbb fbc fbe fbf fbg fbk fbr fbu fcb fcc fce fcf fcg fck fcr fcu feb fec fee fef feg fek fer feu ffc ffe fff ffg ffk ffr ffu fgb fgc fge fgf fgg fgr fkb fkc fkf fkg fkk frb frc fre frf frg frk frr fru fub fue fuf fug fuk fur fuu gbc gbe gbf gbg gbk gbr gbu gcb gcc gce gcf gcg gck gcr gcu ge- geb gec gee gef geg gek ger geu gfb gfc gfe gff gfk gfr ggb ggc ggg ggr ggu gkb grb grc gre grf grg grk grr gru gu- gub guc gue guf gug guk gur guu kbb kbc kbe kbf kbk kbr kbu kcb kcc kce kcg kck kcr kcu ke- keb kec kee kef keg kek ker kfc kff kfg kfu kgb kgc kgf kgu kkb kkc kke kkk kkr kku krc krf krg krk krr kru kub kuc kue kug kuk kur kuu rbb rbc rbe rbf rbg rbk rbr rbu rcb rcc rce rcf rcg rcr rcu re- reb rec ree ref reg rek rer reu rfb rfc rfe rff rfg rfk rfr rfu rgb rgc rge rgf rgg rgk rgr rkb rkc rke rkf rkg rkk rku rrb rrc rrf rrg rrk rrr rru rub ruc rue ruf rug ruk rur ruu ubb ubc ube ubf ubg ubk ubr ubu ucb ucc uce ucf ucg uck ucr ucu ueb uec uee uef ueg uer ufc ufe uff ufg ufr ufu ugb ugc uge ugf ugg ugk ugr ugu ukb ukc uke ukf ukk ukr uku ur- urb urc ure urf urg urk urr uru uuc uue uug uur uuu