Spreadsheet columns are labelled A=1, B=2, ..., Z=26, AA=27, and so on. This is bijective base-26: there is no digit zero, so the usual base conversion needs a correction at each step.
Given a 1-based column number, output its letter label.
Input format
One line: an integer n (the column number).
Output format
One line: the column label in uppercase letters.
Constraints
- 1 <= n <= 1000000000