bbbb bbrg bibb bibi bibo bigb bigg bigo bigt bio- biog bioi biot birb birg biri biro birr birt bito bitt bobb bobi bobo bogg bogi bogo bogt boi- boii boit boob boog boor boot bor- borg bori boro borr bort botb boti boto bott brig brio brit brob brog broo bror brot brrr btob btor btrt bttb gbbo ggbt gggg gibb gigg gigi gigo giog gioi girg giri giro girr girt gito gobi gobo gogi gogo goit goog gooi goor goot gorb gorg gori goro gorr gort goti goto gott grbr grib grig grit grob grog groi groo gror grot grrr gtbr i-go ibot ibri ibro ibtb igbo igoo igor igot igri iiii iiio iiit iioi iioo iitr iitt iobi iogt ioii ioio ioit iooi iooo iorg iori ioto iri- irig irio irob irri irti itgo itoi itoo itor itri itto obbo obit oboi obor obot obri obro ogb oggi ogog ogoi ogri ogro oigo oiii oirt oiti oobi oooo oort ootb orbb orbi orbo orgo ori- orig orio orit oro- oror orot orri orro orto otit oto- otog otoo otor otro otti otto rbbb rbbr rgbi rgit rgtr rib- ribo rigg rigi rigo riot riri riti rito ritt rob- robb robi robo robt rogg rogi rogo roig roio roir roit roob roog rooi roor root rori roro rort rotg roti roto rotr rott rrrr tbit tbrb tibi tigi tigr tiit tirb tiri tiro tirr titi tito titt tobi tobo tobt togo togr togt toit toor toot torg tori toro torr tort toti toto totr tott tri- trib trig trio trit trog troi troo trot trtr ttbb tttt