A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 * 99.

Find the largest palindrome made from the product of two 3-digit numbers.

There are shorter ways to do this, and I cheat a bit by counting down to 900 rather than 100, but this one short-circuits when it finds the answer, and so is very efficient.