-er b-u bbb bbe bbm bbn bbo bbr bbu bbx be- beb bee bem ben beo ber beu bex bmb bme bmm bmn bmo bmr bmu bmx bnb bne bnn bno bnr bnu bnx bob boe bom bon boo bor bou box brb bre brm brn bro brr bru brx bub bue bum bun buo bur buu bux bxb bxm bxn bxo bxx ebb ebe ebm ebn ebo ebr ebu ebx eeb eee eem een eeo eer eex em- emb eme emm emn emo emr emu emx en- enb ene enm enn eno enr enu eo- eob eoe eom eon eoo eor eou erb ere erm ern ero err eru eu- eub eue eun eur eux ex- exe exo exr exu exx m-o m-r mbb mbe mbm mbo mbr mbu mbx meb mee mem men meo mer meu mex mmb mme mmm mmn mmo mmr mmu mmx mnb mne mnm mnn mno mnr mnu mob moe mom mon moo mor mou mox mrb mre mrm mrn mro mrr mru mrx mub mue mum mun mur muu mux mxn mxr mxu nbb nbe nbm nbn nbo nbr nbu nbx ne- neb nee nem nen neo ner neu nex nmb nme nmm nmn nmo nmr nmu nnb nne nnm nnn nno nnu no- nob noe nom non noo nor nou nox nrb nre nrm nrn nro nrr nru nrx nub nue num nun nuo nur nuu nux ob- obb obe obm obn obo obr obu obx oeb oee oem oen oeo oer oex om- omb ome omm omn omo omr omu omx on- onb one onn ono onr onu onx oo- oob oom oon ooo oor oox or- orb ore orm orn oro orr oru orx ou- oue oum oun ouo our ox- oxb oxn oxo oxx rbb rbe rbm rbn rbo rbr rbu rbx re- reb ree rem ren reo rer reu rex rmb rme rmm rmn rmo rmr rmx rnb rnm rnn rno rnr rnu rob roe rom ron roo ror rou rox rrb rrm rrn rrr rru rub rue rum run ruo rur ruu rux rxr ubb ube ubn ubo ubr ubu ubx ueb uee uem uen uer um- umb ume umm umn umo umr umu un- unb une unm unn uno unr unu unx uob uoe uom uon uoo uor uox ur- urb ure urm urn uro urr uru urx uue uum uun uur uuu uxb uxo uxr uxu xbe xbr xbx xee xem xen xer xeu xex xmm xmo xmr xmu xmx xno xnu xom xon xoo xor xox xrx xue xun xxo xxx