+16 William writes the integers from 2 through 15 from left to right on a piece of paper, then does the following:
* He begins by circling the leftmost uncircled integer, then circles all its powers. Afterwards, he repeats this process until every integer is circled.
* Then he crosses off the rightmost uncrossed integer, then crosses off all even numbers less than it in decreasing order. Afterwards, he repeats this process until every integer is crossed off.
Find the product of the last integer William circled and the last integer William crossed off.
