import java.util.Scanner; public class Test { public static Scanner sc = new Scanner(System.in); public static void main(String[] args) { long n = sc.nextLong(); String s = ""; s += (char) ('A' + (n % 26)); n /= 26; while (n > 0) { if (n % 27 > 0) { s = (char) ('A' + (n % 27) - 1) + s; } n /= 27; } System.out.println(s); } }