-er bbb bbe bbm bbo bbr bbx be- beb bee bem beo ber bex bez bmb bme bmm bmo bmr bmx bmz bob boe bom boo bor box boz brb bre brm bro brr brx brz bxb bxm bxo bxx bze bzo bzr bzz ebb ebe ebm ebo ebr ebx eeb eee eem eeo eer eex em- emb eme emm emo emr emx eo- eob eoe eom eoo eor erb ere erm ero err erz ex- exe exo exr exx eze ezo ezr ezz m-o m-r mbb mbe mbm mbo mbr mbx meb mee mem meo mer mex mez mmb mme mmm mmo mmr mmx mmz mob moe mom moo mor mox moz mrb mre mrm mro mrr mrx mrz mxr mzb mzm mzx ob- obb obe obm obo obr obx oeb oee oem oeo oer oex om- omb ome omm omo omr omx omz oo- oob oom ooo oor oox or- orb ore orm oro orr orx orz ox- oxb oxo oxx oze ozm ozo ozz rbb rbe rbm rbo rbr rbx re- reb ree rem reo rer rex rez rmb rme rmm rmo rmr rmx rob roe rom roo ror rox roz rrb rrm rrr rxr rzb rze rzm rzo xbe xbr xbx xee xem xer xex xmm xmo xmr xmx xom xoo xor xox xrx xxo xxx zbb zbm zbr zeb zee zem zeo zer zez zmb zmm zo- zob zoe zom zoo zor zox zro zxx zzr zzx zzz