-er b-u bbb bbc bbe bbg bbk bbn bbo bbr bbu bcb bcc bce bcg bck bcn bco bcr bcu be- beb bec bee beg bek ben beo ber beu bgb bgc bge bgg bgk bgn bgo bgr bgu bkb bkc bke bkg bkk bkn bko bkr bnb bnc bne bng bnk bnn bno bnr bnu bob boc boe bog bok bon boo bor bou brb bre brg brk brn bro brr bru bub buc bue bug buk bun buo bur buu c-- cbb cbc cbe cbg cbk cbn cbo cbr cbu ccb ccc cce ccg cck ccn cco ccr ccu ce- ceb cec cee ceg cek cen ceo cer ceu cgb cgc cge cgg cgn cgo cgr cgu ckb ckc cko cn- cnb cnc cne cng cnn cno cnr cnu co- cob coc coe cog cok con coo cor cou crb crc cre crg crk crn cro crr cru cub cuc cue cug cuk cun cuo cur cuu ebb ebc ebe ebg ebk ebn ebo ebr ebu ec- ecb ecc ece ecg eck ecn eco ecr ecu eeb eec eee eeg eek een eeo eer egb egc ege egg egn ego egr egu ekb ekc eke ekg eko ekr eku en- enb enc ene eng enk enn eno enr enu eo- eob eoc eoe eog eok eon eoo eor eou erb erc ere erg erk ern ero err eru eu- eub euc eue eug eun eur gbc gbe gbg gbk gbn gbo gbr gbu gcb gcc gce gcg gck gcn gco gcr gcu ge- geb gec gee geg gek gen geo ger geu ggb ggc ggg ggn ggo ggr ggu gkb gkn gko gnb gnc gne gnn gno gnr gnu gob goc goe gog gok gon goo gor gou grb grc gre grg grk grn gro grr gru gu- gub guc gue gug guk gun guo gur guu kbb kbc kbe kbk kbn kbo kbr kbu kcb kcc kce kcg kck kcn kcr kcu ke- keb kec kee keg kek ken keo ker kgb kgc kgo kgu kkb kkc kke kkk kkn kkr kku kn- knc kne kng knk knn kno knr knu kob koc koe kog kok kon koo kor kou krc krg krk krn kro krr kru kub kuc kue kug kuk kun kur kuu nbb nbc nbe nbg nbk nbn nbo nbr nbu ncb ncc nce ncg nck ncn nco ncr ncu ne- neb nec nee neg nek nen neo ner neu ngb ngc nge ngg ngk ngn ngo ngu nkc nke nkk nkn nko nkr nku nnb nnc nne nng nnk nnn nno nnu no- nob noc noe nog nok non noo nor nou nrb nrc nre nrg nrk nrn nro nrr nru nub nuc nue nug nuk nun nuo nur nuu ob- obb obc obe obg obk obn obo obr obu oc- ocb occ ocg ock ocn oco ocr ocu oeb oec oee oeg oen oeo oer ogc oge ogg ogn ogo okb okc oke okg okk oko okr oku on- onb onc one ong onk onn ono onr onu oo- oob ooc oog ook oon ooo oor or- orb orc ore org ork orn oro orr oru ou- ouc oue ouk oun ouo our rbb rbc rbe rbg rbk rbn rbo rbr rbu rcb rcc rce rcg rcn rco rcr rcu re- reb rec ree reg rek ren reo rer reu rgb rgc rge rgg rgk rgn rgo rgr rkb rkc rke rkg rkk rko rku rnb rnc rng rnn rno rnr rnu rob roc roe rog rok ron roo ror rou rrb rrc rrg rrk rrn rrr rru rub ruc rue rug ruk run ruo rur ruu ubb ubc ube ubg ubk ubn ubo ubr ubu ucb ucc uce ucg uck ucn uco ucr ucu ueb uec uee ueg uen uer ugb ugc uge ugg ugk ugn ugo ugr ugu ukb ukc uke ukk ukn ukr uku un- unb unc une ung unk unn uno unr unu uob uoc uoe uog uok uon uoo uor ur- urb urc ure urg urk urn uro urr uru uuc uue uug uun uur uuu