4 letter words:
biog7,
upgo7,
3 letter words:
bop7,
pub7,
big6,
bog6,
bug6,
gib6,
gip6,
gob6,
gub6,
gup6,
pig6,
pug6,
bio5,
boi5,
obi5,
oup5,
piu5,
poi5,
upo5,
gio4,
2 letter words:
bi4,
bo4,
ob4,
op4,
pi4,
po4,
up4,
gi3,
go3,
gu3,
ug3,
io2,
oi2,
ou2,