5 letter words:
fermi10,
preif10,
prief10,
prime9,
4 letter words:
ferm9,
firm9,
perm8,
prem8,
prim8,
fier7,
fire7,
reif7,
rife7,
emir6,
meri6,
mire6,
peri6,
pier6,
riem6,
rime6,
ripe6,
3 letter words:
fem8,
imp7,
erf6,
fer6,
fie6,
fir6,
ref6,
rif6,
mir5,
per5,
pie5,
pir5,
pre5,
rem5,
rep5,
rim5,
rip5,
ire3,
rei3,
2 letter words:
ef5,
fe5,
if5,
em4,
me4,
mi4,
pe4,
pi4,
er2,
re2,