5 letter words:
fibro10,
oribi7,
4 letter words:
firk11,
fork11,
birk10,
bork10,
brik10,
forb9,
frib9,
biro6,
brio6,
3 letter words:
kif10,
bok9,
kob9,
fib8,
fob8,
irk7,
kir7,
koi7,
kor7,
oik7,
rok7,
fir6,
for6,
fro6,
orf6,
rif6,
bio5,
boi5,
bor5,
bro5,
obi5,
orb5,
rib5,
rob5,
2 letter words:
ki6,
ko6,
if5,
of5,
bi4,
bo4,
ob4,
io2,
oi2,
or2,