5 letter words:
orris5,
4 letter words:
firs7,
foss7,
fris7,
fros7,
orfs7,
rifs7,
isos4,
sirs4,
sori4,
sris4,
3 letter words:
fir6,
for6,
fro6,
ifs6,
orf6,
rif6,
sif6,
ios3,
iso3,
ors3,
sir3,
sis3,
sos3,
sri3,
2 letter words:
if5,
of5,
io2,
is2,
oi2,
or2,
os2,
si2,
so2,