bbbb bblb bcbc bccc bccl bctc blbt blob bloc bloo blot bobb bobo boco boll bolo bolt boob booc bool boot botb boto bott btcc btcl btob bttb c-bo cbbc cbcc cbcl cbct cblb cblc cbol cbot cbtc cbtl ccbc cccb cccc cccl cclc ccob ccoc cctb cctc cctl cctt clob cloo clot cltb cltc cobb cobo coco coct col- colb coll colo colt coob cool coot cotb cotc coto cott ctol ctot lbcc lcbc lccc lctl lcto llcc lllc llll lloc lloo lob- lobb lobo locc loco loll lolo loob looc lool loot lotl loto lott ltbl ltcc lttc obbo obol obot ocbc occc occt oclc oct- octo olbo olcc ollo olot oolo oooo ootb otcl oto- otoo otto tbcb tbcc tccc tctc tlco tobo tobt toco tol- toll tolo tolt tool toot totc toto tott ttbb tttt