There are three different a, b, and c, which can form 6 different three-digit numbers. It is known that the sum of these six three-digit numbers is 4440. What is the largest three-digit number among them?
有三个不同的a、b、c，能组成6个不同的三位数，已知这六个三位数的和是4440，其中最大的一个三位数是多少．
<result>983</result>