Continuously write natural numbers starting from l until 2009, and get a multi-digit number 123456789...20082009. Please explain: When this multi-digit number is divided by 3, what is the remainder? Why?
连续从l开始的自然数，写到2009为止，得到一个多位数123456789…20082009．请说明：这个多位数除以3，得到的余数是几？为什么？
<result>3</result>