12^15 mod 17
Just split it up into easier segments.
\(12^{15}\; mod \;17\\ =(12^3)^5\; mod \;17\\ =(1728)^ 5 \; mod \;17\\ =(17*101+11)^ 5 \; mod \;17\\ =(11)^ 5 \; mod \;17\\ =(161051) \; mod \;17\\ =(9473*17+10) \; mod \;17\\ =10\)
