bbbb bbeb bbet bebb bebe bebo beeb beef beet befe beff befo beft beo- beof beot bete beto bett bftt bobb bobe bobo boee boef boeo boet bofe boff boob booe boof boot botb bote boto bott btob bttb ebbo eboe eboo eeee eefe eete efeo efet eft- eoto etee etfb etfe etoe ette etto febo feeb feet fefe feff fefo feof fete fett ffee ffff fftf fobt fofo foof foot fote foto fott o-eo obbo obet oboe obot off- offe offo oobe ooff oooo ootb otee oto- otoe otof otoo otte otto tebo teef teet teff teft tete teto tett tfeb tfot tobe tobo tobt toee toet toff tofo toft toof toot tote toto tott ttbb tteo ttff ttoe tttt