The encoded text is:
EXAMPLE
And the method of encoding is
Strip spaces, then treat the full string as a cycle of text, each
position in the encoded string is the sum of the two positions next to
it in the unencoded string.
Example using "fair game"
e+a = f; f+i = o; a+r=s; i+g=p; r+a=s;g+m=t;a+e=f;m+f=s FAIR GAME => FOSPSTFS
THUS: FAIR GAME => FOSPSTFS
