5 letter words:
kerfs12,
4 letter words:
kefs11,
kerf11,
kues8,
rusk8,
ukes8,
feus7,
furs7,
fuse7,
refs7,
serf7,
surf7,
rues4,
ruse4,
suer4,
sure4,
user4,
3 letter words:
kef10,
kue7,
suk7,
uke7,
efs6,
fer6,
fes6,
feu6,
fur6,
ref6,
ers3,
res3,
rue3,
ser3,
sue3,
use3,
2 letter words:
ef5,
fe5,
er2,
es2,
re2,
us2,