-ol bbb bbd bbl bbo bbr bbt bdb bdd bdl bdo bdr bdt blb bld bll blo blr blt bob bod bol boo bor bot brb brd brl bro brr brt btb btd btl bto btr btt dbb dbd dbl dbo dbr dbt ddb ddd ddl ddo ddr ddt dl- dlb dld dll dlo dlr dlt dob dod dol doo dor dot drb drd drl dro drr drt dtb dtd dtl dto dtr dtt lbb lbd lbl lbo lbr lbt ldb ldd ldl ldo ldr ldt llb lld lll llo llr llt lob lod lol loo lor lot lrb lrd lro lrr lrt ltb ltd ltl lto ltr ltt ob- obb obd obl obo obr obt odb odd odl odo odr odt olb old oll olo olt oo- oob ood ool ooo oor oot or- orb ord orl oro orr ort ot- otb otd otl oto otr ott rbb rbd rbl rbo rbr rbt rdb rdd rdl rdo rdr rdt rld rll rlo rlr rlt rob rod rol roo ror rot rrb rrd rrl rrr rrt rtb rtd rtl rto rtr rtt tbb tbd tbl tbo tbr tbt tdb tdd tdl tdo tdr tdt tld tll tlo tlr tlt to- tob tod tol too tor tot trb trd trl tro trr trt ttb ttd ttl tto ttr ttt