Alg6.1.1
From Exampleproblems
Considering that:

and that:
,
,
,
then,

Just take the exponent, find the remainder after dividing by 4 (the modulus) and the exponent of 1, 2, 3, or 4 tells you what you have. All the other powers of 4 will just be
, and can be discarded.
