package no153;

import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		int[] grundy = new int[101];
		for(int i=2;i<=100;i++) {
			PriorityQueue<Integer> s = new PriorityQueue<>();
			s.add(grundy[i/2] ^ grundy[(i+1)/2]);
			if (i >= 3) {
				s.add(grundy[i/3] ^ grundy[(i+1)/3] ^ grundy[(i+2)/3]);
			}
			s.add(999);
			for(int j=0;j<3;j++) {
				if (s.poll() != j) {
					grundy[i] = j;
					break;
				}
			}
		}
//		System.out.println(Arrays.toString(grundy));

		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		System.out.println(grundy[n] == 0 ? "B" : "A");
	}
}