bbbb bblb bibb bibi bibl bibo bili bill bilo bilt bio- bioi biol biot birb biri birl biro birr birt bito bitt blbt blio blir blit blob bloo blot bobb bobi bobo boi- boii boil boit boli boll bolo bolt boob bool boor boot bor- bori boro borr bort botb boti boto bott bril brio brit brob brol broo bror brot brrr btob btor btrt bttb ibot ibri ibro ibtb ibtl iiii iiio iiit iioi iioo iitr iitt ilio ilir ilit ill- illi illo illt iloo ilot iobi ioii ioio ioit iolo iooi iooo iori ioto iri- iril irio irlb irob irri irti itil itll itoi itol itoo itor itri itto lblr lbrt libo libr liii liir lilb lili lill lilo lilt lio- lior liri lirl liro lirr lirt litb liti litl lito litr litt llll lloo lob- lobb lobi lobo loir loit loli loll lolo loob lool loor loot lori loro loti lotl loto lotr lott lroi lrrr ltbl ltib lttr obbo obit oboi obol obor obot obri obro oiii oirt oiti olbo olib olio olit olli ollo olor olot oobi oolo oooo oort ootb orbb orbi orbo ori- oril orio orit orlo oro- oror orot orri orro orto otit oto- otoo otor otro otti otto rbbb rbbr rib- ribo rill rilo riol riot riri riti ritl rito ritt rob- robb robi robo robt roil roio roir roit roll rolo rolt roob rooi rool roor root rori roro rort roti rotl roto rotr rott rrrr rtlt tbil tbit tbrb tibi tiit till tilo tilr tilt tirb tiri tirl tiro tirr titi tito titt tlli tobi tobo tobt toil toit tol- toli toll tolo tolt tool toor toot tori toro torr tort toti toto totr tott tri- trib tril trio trit troi troo trot trtr ttbb tttt