-ol bbb bbl bbo bbs bbt blb bll blo bls blt blv bob bol boo bos bot bov bsb bsl bso bss bst bsv btb btl bto bts btt btv bvb bvl bvo bvs bvt bvv lbb lbl lbo lbs lbt lbv llb lll llo lls llt llv lob lol loo los lot lov lsb lsl lso lss lst lsv ltb ltl lto lts ltt ltv lvb lvl lvs lvt lvv ob- obb obl obo obs obt obv olb oll olo ols olt oo- oob ool ooo oos oot oov os- osb osl oso oss ost osv ot- otb otl oto ots ott otv ov- ovb ovl ovo ovs ovv sbb sbl sbo sbs sbt sbv slb sll slo sls slt slv sob sol soo sos sot sov ss- ssb ssl sso sss sst ssv stb stl sto sts stt stv svb svl svo svs svt svv tbb tbl tbo tbs tbt tbv tll tlo tls tlt tlv to- tob tol too tos tot tov tsb tsl tso tss tst tsv ttb ttl tto tts ttt ttv tvb tvl tvo tvs tvt vbl vbo vbs vbv vl- vlb vll vlo vls vlt vlv vob vol voo vos vot vov vsb vsl vso vss vst vsv vtb vtl vto vts vtt vtv vvb vvo vvs vvt vvv