For an assignment, I've been asked to evaluate $7^{10507} \bmod 13$.
I know it's possible to do this using binary fast exponentiation - in fact the question refers to a previous question where I calculated $7^{12} \bmod 13$ to help prove $13$ is prime using Fermat's Little Theorem.
I could simply perform the exponentiation, but I feel like I'm missing some way to simplify the question here - why bother referencing the $7^{12}$ question if I couldn't somehow use it to simplify my task.
Is there some sort of simplification I can perform here? Am I missing something?