Fill in the number in "□" of "3□7□" so that it becomes the largest four-digit number that is divisible by 2, 3, and 5 at the same time. What is the four-digit number?
在"3□7□"的"□"里填上数，使它成为同时被2、3、5整除的最大的四位数，这个四位数是多少．
<result>3_870</result>