Equation: Chaozhou 54=39*1 city 6 happens to have nine numbers 1, 2, 3, 4, ..., 9, what is the three-digit number represented by "Chaozhou".
等式：潮州54=39*1市6恰好出现1、2、3、4、…、9九个数字，"潮州市"代表的三位数是多少．
<result>728</result>