Problem 4

Largest palindrome product

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

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

回文数是指从前往后读和从后往前读都一样的数。由两个$2$位数相乘得到的回文数中，最大的是 $9009 = 91 \times 99$。

求最大的由两个$3$位数相乘得到的回文数。