There are five numbers 0, 1, 4, 7, and 9. Select four numbers from them to form different four-digit numbers. If you arrange the four-digit numbers divisible by 3 from small to large, the end of the fifth number What is the number of digits.
有0、1、4、7、9五个数字，从中选出四个数字组成不同的四位数，如果把其中能被3整除的四位数从小到大排列起来，第五个数的末位数字是多少．
<result>9</result>