4 letter words:
loop6,
loup6,
noop6,
noup6,
polo6,
pool6,
poon6,
upon6,
loon4,
loun4,
nolo4,
noul4,
3 letter words:
lop5,
oop5,
oup5,
plu5,
pol5,
poo5,
pul5,
pun5,
upo5,
loo3,
lou3,
noo3,
ono3,
oon3,
2 letter words:
op4,
po4,
up4,
lo2,
no2,
nu2,
on2,
oo2,
ou2,
un2,