Given a time represented in the format "HH:MM", form the next closest time by reusing the current digits. There is no limit on how many times a digit can be reused.
You may assume the given input string is always valid. For example, "01:34", "12:09" are all valid. "1:34", "12:9" are all invalid.
Example 1:
Input: "19:34" Output: "19:39" Explanation: The next closest time choosing from digits 1 , 9 , 3 , 4 , is 19:39 , which occurs 5 minutes later. It is not 19:33 , because this occurs 23 hours and 59 minutes later.
Example 2:
Input: "23:59" Output: "22:22" Explanation: The next closest time choosing from digits 2 , 3 , 5 , 9 , is 22:22 . It may be assumed that the returned time is next day's time since it is smaller than the input time numerically.