/* -*- coding: utf-8 -*-
 *
 * 153.cc: No.153 石の山 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100;

/* typedef */

typedef vector<int> vi;

/* global variables */

int gndys[MAX_N + 1];
bool used[MAX_N + 1];

/* subroutines */

/* main */

int main() {
  int n;
  cin >> n;

  gndys[0] = gndys[1] = 0;

  for (int i = 2; i <= n; i++) {
    memset(used, false, sizeof(used));

    used[gndys[i / 2] ^ gndys[(i + 1) / 2]] = true;
    if (i >= 3)
      used[gndys[i / 3] ^ gndys[(i + 1) / 3] ^ gndys[(i + 2) / 3]] = true;

    for (gndys[i] = 0; used[gndys[i]]; gndys[i]++);
  }

  printf("%c\n", (gndys[n] != 0) ? 'A' : 'B');
  return 0;
}