bbb bbc bbh bbk bbo bcb bcc bch bck bco bcv bhb bhc bhh bhk bho bhv bkb bkc bkk bko bkv bob boc boh bok boo bov bvb bvc bvh bvk bvo bvv c-- cbb cbc cbh cbk cbo cbv ccb ccc cch cck cco ccv ch- chb chc chh chk cho chv ckb ckc ckh cko co- cob coc coh cok coo cov cvb cvc cvh cvk cvo cvv hbb hbc hbh hbk hbo hbv hcb hcc hch hck hco hcv hhb hhc hhh hhk hho hhv hkb hkh hkk hko hob hoc hoh hok hoo hov hv- hvb hvc hvk hvo hvv kbb kbc kbh kbk kbo kcb kcc kch kck khh khk kho khv kkb kkc kkh kkk kkv kob koc koh kok koo kvb kvh kvk kvo kvv ob- obb obc obh obk obo obv oc- ocb occ och ock oco ocv ohc ohh oho okb okc okk oko oo- oob ooc ooh ook ooo oov ov- ovb ovc ovh ovo ovv vbc vbh vbk vbo vbv vcc vch vco vh- vhb vhc vho vkb vob voc voh vok voo vov vvb vvc vvo vvv