bbbb bbpr bibb bibi bibo bio- bioi biot bipp birb biri biro birr birt bito bitt bobb bobi bobo boi- boii boit boob boop boor boot bopp bor- bori boro borr bort botb boti boto bott bpot bpti brio brit brob broo bror brot brrr btbp btob btor btrt bttb ibot ibri ibro ibtb iiii iiio iiit iioi iioo iiop iitr iitt iobi ioii ioio ioit iooi iooo iori ioto ipop ippo ippr ipri ipto irbp iri- irio irip irob irop irri irti irtp itoi itoo itor itri itto obbo obit oboi obor obot obri obro oiii oirt oiti oobi oooo oort ootb ootp opii opio opit opo- opor oppi oppo opti opto orbb orbi orbo ori- orio orit oro- oror orot orpi orri orro orto otit oto- otoo otor otpp otro otti otto pibb pibi piip piob piot pipi pipo pipp piri piro pirr piti pito pitr pitt pobo poio poop poor poot pop- popi popo popp popt porb pori poro porr port poti poto pott ppib pppo pppp pptt pri- prii pro- prob proo prop prot prri prti prtp prtr ptop rbbb rbbr rib- ribo riot ripi ripp ripr ript riri riti rito ritt rob- robb robi robo robt roio roir roit roob rooi roop roor root ropo rori roro rort roti roto rotr rott rpii rpob rrrr rttp tbit tbrb tbtp tibi tiit tiop tip- tipi tipo tipp tipt tirb tiri tiro tirr titi tito titp titt tobi tobo tobt toit toor toot top- topi topo topp topt tori toro torp torr tort toti toto totr tott tpir tppp tppr tptp tptr tri- trib trio trip trit troi troo trop trot trpp trtr ttbb ttop tttt