-er bbb bbe bbm bbo bbr bbt be- beb bee bem beo ber bet bmb bme bmm bmo bmr bmt bob boe bom boo bor bot brb bre brm bro brr brt btb bte btm bto btr btt ebb ebe ebm ebo ebr ebt eeb eee eem eeo eer eet em- emb eme emm emo emr emt eo- eob eoe eom eoo eor eot erb ere erm ero err ert etb ete etm eto etr ett m-o m-r mbb mbe mbm mbo mbr mbt meb mee mem meo mer met mmb mme mmm mmo mmr mmt mob moe mom moo mor mot mrb mre mrm mro mrr mrt mtb mte mtm mto mtr mtt ob- obb obe obm obo obr obt oeb oee oem oeo oer oet om- omb ome omm omo omr omt oo- oob oom ooo oor oot or- orb ore orm oro orr ort ot- otb ote otm oto otr ott rbb rbe rbm rbo rbr rbt re- reb ree rem reo rer ret rmb rme rmm rmo rmr rmt rob roe rom roo ror rot rrb rrm rrr rrt rtb rte rtm rto rtr rtt tbb tbe tbm tbo tbr tbt te- teb tee tem teo ter tet tmb tme tmm tmo tmr tmt to- tob toe tom too tor tot trb tre trm tro trr trt ttb tte ttm tto ttr ttt