You are given an integer n.
A number is called special if:
k in the number appears exactly k times.Return the smallest special number strictly greater than n.
Example 1:
Input: n = 2
Output: 22
Explanation:
22 is the smallest special number greater than 2, as it is a palindrome and the digit 2 appears exactly 2 times.
Example 2:
Input: n = 33
Output: 212
Explanation:
212 is the smallest special number greater than 33, as it is a palindrome and the digits 1 and 2 appear exactly 1 and 2 times respectively.
Constraints:
0 <= n <= 1015