bbbb bblb bibb bibi bibl bibo bili bill bilo bio- bioi biol birb biri birl biro birr bivi bivl blio blir blob bloo bobb bobi bobo boi- boii boil boli boll bolo boob bool boor bor- bori boro borr bovi bovo bril brio brob brol broo bror brrr brvi ibri ibro iiii iiio iioi iioo ilio ilir ill- illi illo iloo iobi ioii ioio iolo iooi iooo iori iri- iril irio irlb irob irov irri ivbv ivor lblr libo libr liii liir liiv lilb lili lill lilo lio- lior liri lirl liro lirr livi livo llll lloo lo-v lob- lobb lobi lobo loir loli loll lolo loob lool loor lori loro lovo lroi lrrr lvii lviv lvov lvrr obbo oboi obol obor obri obro obvi oiii olbo olib olio olli ollo olor olov olvi oobi oolo oooo orbb orbi orbo ori- oril orio orlo oro- oror orri orro orvr ovi- ovil ovo- ovol ovoo rbbb rbbr rib- ribo rill rilo riol riri rivo rob- robb robi robo roil roio roir roll rolo roob rooi rool roor rori roro rovi rovo rrrr viii vili vill viol virb viri virl viro virr vivi vivo vlli voil voio voir voli voll volo vool voor vor- vori voro vrbl vril vrio vvob vvvv