Algorthim Analysis Question

Demonstrate how to perform the slick, efficient modular exponentiation algorithm, using a calculator, for a = - 29613, e = 8075, working in Z31861. Remember that to compute, say, a in Zn, you first do a2 = 29613 29613 = 876929769, and then reduce it mod n by dividing by n = 31861, obtaining 876929676/31861 27523.610966385235868, then subtract the integer part, obtaining 0.6109663852385868 and then multiply by 31861 to get the remainder: 0.6109663852385868 31861 = 19466