bbb bbg bbo bbs bbt bgb bgg bgo bgs bgt bob bog boo bos bot bsb bsg bso bss bst btb btg bto bts btt gbg gbo gbs gbt ggb ggg ggo ggs ggt gob gog goo gos got gsb gsg gso gss gst gtb gtg gto gts gtt ob- obb obg obo obs obt ogg ogo ogs ogt oo- oob oog ooo oos oot os- osb osg oso oss ost ot- otb otg oto ots ott sbb sbg sbo sbs sbt sgb sgg sgo sgs sgt sob sog soo sos sot ss- ssb ssg sso sss sst stb stg sto sts stt tbb tbg tbo tbs tbt tgb tgg tgo tgs tgt to- tob tog too tos tot tsb tsg tso tss tst ttb ttg tto tts ttt