Given a positive integer n, return its corresponding string representation in a base-26 system where digits are mapped to uppercase English letters (A to Z). The mapping is such that 1 maps to A, 2 to B, ..., 26 to Z, 27 to AA, 28 to AB, and so on.
Example 1
Input: n = 52
Output: AZ
Explanation: 52 maps to AZ in Excel column title system.
Example 2
Input: n = 703
Output: AAA
Explanation: 703 maps to AAA in Excel column title system.
Example 3
Input: n = 18278
Output: ZZZ
Explanation: 18278 maps to ZZZ in Excel column title system.
Constraints
Case 1
Input: n = 100
Expected: 'CV'
Case 2
Input: n = 260
Expected: 'JD'
Case 3
Input: n = 1378
Expected: 'BZZ'
Case 4
Input: n = 475254
Expected: 'ZZZZ'
Case 5
Input: n = 702
Expected: 'ZZ'