-ol bbb bbl bbm bbo bbt blb bll blm blo blt bmb bml bmm bmo bmt bob bol bom boo bot btb btl btm bto btt lbb lbl lbm lbo lbt llb lll llm llo llt lmb lml lmm lmo lmt lob lol lom loo lot ltb ltl ltm lto ltt m-o mbb mbl mbm mbo mbt mlb mll mlm mlo mlt mmb mml mmm mmo mmt mob mol mom moo mot mtb mtl mtm mto mtt ob- obb obl obm obo obt olb oll olm olo olt om- omb oml omm omo omt oo- oob ool oom ooo oot ot- otb otl otm oto ott tbb tbl tbm tbo tbt tll tlm tlo tlt tmb tml tmm tmo tmt to- tob tol tom too tot ttb ttl ttm tto ttt