You can
put this solution on YOUR website!
The smallest FIVE can be is 5153 like this
2980
+2173
-----
5153
or we can swap the 8 and 7 and get the same thing.
I know of no way but trial and error. You can see right
off that R=0 and O=9 and that we carry 1 to the leftmost
two columns. Then we try N to be 1 making N=3, and
that ends up a failure. So we try F=2 making N=5, and
succeed with I as small as it can be, 1.
Edwin