Bitwise XOR used instead of squaring

[MarksonChen]

At this line:

247310/mfm.py

Line 156 in d010593

self.gammasq=self.gammae^2

The code used ^ (bitwise xor), but I believe the intention was to use **.
As a result, gammasq = 125^2 = 127 instead of gammasq = 125**2 = 15,625.