bbbb bibb bibi bibo bimo bio- bioi biou birb biri biro birr biru bmir bmmi bobb bobi bobo bobu boi- boii boim boiu bomb bomi bomu boob boom boor bor- bori borm boro borr boru boum bour brim brio brob brom broo bror brou brrm brrr brum bubb bubi bubo bubu buir buiu bum- bumb bur- burb buri burm buro burr buru ibbm ibim ibri ibro iiii iiio iioi iioo iium imbi imir immi immo imou imri imro imrr iobi ioii ioio iomo iooi iooo iori irbm iri- irio irmo irob irri iuiu mbim mbio mbou miii miio mim- mimi mimo mio- miri miro mirr miru miui mmii mmmm mmor mobb mobi mobo moii moio moir momi momo momu moob moor morb mori moro moru mour mrbb mrbm mubi mubo muir mumm mumo mumu muri muro murr muru obbo oboi obor obri obro oiii oimb oium ombo ombu omim omio omo- omoi omoo omor omri omro omuo oobi oooo orbb orbi orbo orbu ori- orio ormo oro- orom oror orri orro orub orum ouii ouir oumi our- ouro ouu- rbbb rbbr rib- ribo ribu rimi rimm rimo rimu riom riou riri rob- robb robi robo robu roio roir roiu romb romi romm romo roob rooi room roor rori roro roru roub roum rrrr rrum rubb rubi rubu rumb rumi rumm rumo ruri ruro ruru ubbi ubbo ubii ubir uirr umb- umbi umbo ummo umor umri uomo uor- urbi urib urim uriu urmi uro- urom uroo urri urum urur uuri uuuu