**Exercise 2.**
This software determines the size of *U(k)*.
Run the program for *k = 9, 27, 81, 243,
25, 125, 49, 121*. On the basis of this
output try to guess a formula for the size of
*U(p ^{n})* as a function of the
prime p and the integer n. Run the program
for

Please enter k here: