Support tickets are numbered TKT-000042 style: the prefix TKT- followed by the ticket number padded with zeros on the left to at least 6 digits. Given the number as a string num (digits only), return the full ticket id. Numbers with more than 6 digits are not cut.
Examples
Input: num = "42"
Output: "TKT-000042"
Input: num = "1234567"
Output: "TKT-1234567"
Constraints
1 <= len(num) <= 12numcontains only the characters0-9
Goals
- Pad a string on the left to a fixed width
- Leave strings that are already wide enough unchanged