Given a positive integer n, find the smallest integer which has exactly the same digits existing in the integer n and is greater in value than n. If no such positive integer exists, return -1.

Note that the returned integer should fit in 32-bit integer, if there is a valid answer but it does not fit in 32-bit integer, return -1.

 

Example 1:

Input: n = 12
Output: 21

Example 2:

Input: n = 21
Output: -1

 

Constraints:

• 1 <= n <= 231 - 1