bbbb bibb bibi bibo bio- bioi biot birb biri biro birr birt bito bitt bitz bivi bizz bobb bobi bobo boi- boii boit boob boor boot booz bor- bori boro borr bort borz botb boti boto bott bovi bovo bozi bozo brio brit briz brob broo bror brot broz brrr brvi btob btor btrt bttb btvi bziv bzzt bzzz ibot ibri ibro ibtb iiii iiio iiit iioi iioo iitr iitt iobi ioii ioio ioit iooi iooo iori ioto iri- irio irob irov irri irti itoi itoo itor itri itto ivbv ivor izzo obbo obit oboi obor obot obri obro obvi oiii oirt oiti oitz oobi oooo oort ootb oozi orbb orbi orbo ori- orio orit oro- oror orot oroz orri orro orto orvr orzo otit oto- otoo otor otov otro otti otto otzi ovi- ovo- ovoo ovot rbbb rbbr rib- ribo riot rioz riri riti rito ritt ritz rivo rizi rizz rob- robb robi robo robt roio roir roit roiz roob rooi roor root rooz rori roro rort roti roto rotr rott rovi rovo rozi rozz rrrr rtvi tbit tbrb tbvi tibi tiit tirb tiri tiro tirr titi tito titt titz tivi tivo tizi tizz tobi tobo tobt toit toor toot tori toro torr tort torv toti toto totr tott tovo tozo tri- trib trio trit triz troi troo trot trtr ttbb tttt tvri tvro tvrr tvtv tzzt viii virb viri viro virr virt viti vito vitt vivi vivo vizt voio voir voit voiz voor voot vor- vori voro vort voto vrio vrot vrto vt-i vvob vvvv z-ro zbvi zibo ziri ziro ziti zito zizi zizz zobo zoio zoo- zoot zorb zori zoro zort zoti zott zotz zozo zzzz