Many states use a sequence of three letters followed by a sequence of three digits as their standard license-plate pattern. Given that each three-letter three-digit arrangement is equally likely, the probability that such a license plate will contain at least one palindrome (a three-letter arrangement or a three-digit arrangement that reads the same left-to-right as it does right-to-left) is $$m/n$$, where $$m$$ and $$n$$ are relatively prime positive integers. Find $$m+n$$.

(第二十届AIME1 2002 第1题)