Use 1, 2, 3, 4, 5, 6, 7 to form three two-digit numbers and one one-digit number, and make the sum of these four numbers equal to 100, requiring the largest two-digit number to be as large as possible. So, what is the largest two-digit number?
用1、2、3、4、5、6、7七个数字组成三个两位数和一个一位数，并且使这四个数之和等于100，要求最大的两位数尽可能大．那么，最大的两位数是多少．
<result>57</result>