b-u bbb bbc bbe bbk bbn bbo bbu bcb bcc bce bck bcn bco bcu be- beb bec bee bek ben beo beu bkb bkc bke bkk bkn bko bnb bnc bne bnk bnn bno bnu bob boc boe bok bon boo bou bub buc bue buk bun buo buu c-- cbb cbc cbe cbk cbn cbo cbu ccb ccc cce cck ccn cco ccu ce- ceb cec cee cek cen ceo ceu ckb ckc cko cn- cnb cnc cne cnn cno cnu co- cob coc coe cok con coo cou cub cuc cue cuk cun cuo cuu ebb ebc ebe ebk ebn ebo ebu ec- ecb ecc ece eck ecn eco ecu eeb eec eee eek een eeo ekb ekc eke eko eku en- enb enc ene enk enn eno enu eo- eob eoc eoe eok eon eoo eou eu- eub euc eue eun kbb kbc kbe kbk kbn kbo kbu kcb kcc kce kck kcn kcu ke- keb kec kee kek ken keo kkb kkc kke kkk kkn kku kn- knc kne knk knn kno knu kob koc koe kok kon koo kou kub kuc kue kuk kun kuu nbb nbc nbe nbk nbn nbo nbu ncb ncc nce nck ncn nco ncu ne- neb nec nee nek nen neo neu nkc nke nkk nkn nko nku nnb nnc nne nnk nnn nno nnu no- nob noc noe nok non noo nou nub nuc nue nuk nun nuo nuu ob- obb obc obe obk obn obo obu oc- ocb occ ock ocn oco ocu oeb oec oee oen oeo okb okc oke okk oko oku on- onb onc one onk onn ono onu oo- oob ooc ook oon ooo ou- ouc oue ouk oun ouo ubb ubc ube ubk ubn ubo ubu ucb ucc uce uck ucn uco ucu ueb uec uee uen ukb ukc uke ukk ukn uku un- unb unc une unk unn uno unu uob uoc uoe uok uon uoo uuc uue uun uuu