import java.util.Scanner; public class Main { public static void main (String[] args) { Scanner sc = new Scanner(System.in); System.out.println(solve(sc.nextLong())); sc.close(); } public static String solve (long n) { String[] alp = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"}; String ret = alp[(int)(n % alp.length)]; n /= alp.length; while (n != 0) { int a = ((int)(n % alp.length)) - 1; if (a == -1) a = alp.length - 1; ret = alp[a] + ret; if (n == alp.length) break; n /= alp.length; } return ret; } }