#include <iostream>
#include <cstring>
using namespace std;

const int MAX_N = 110;

int table[MAX_N][2];   // (石の個数, 偶奇(偶:0, 奇:1))

int judge(int stones, int e_or_o) {
    if (table[stones][e_or_o] >= 0) {
        return table[stones][e_or_o];
    }
    if (stones == 1) {
        return table[stones][e_or_o] = !e_or_o;
    }
    int res = 0;
    if (e_or_o) {
        if (stones % 2 == 0) {
            res = res || !judge(stones / 2, 1);
            res = res || !judge(stones / 2, 0);
        } else {
            res = res || (!judge(stones / 2, 1) && judge(stones / 2 + 1, 1));
            res = res || (!judge(stones / 2, 0) && judge(stones / 2 + 1, 0));
        }

        if (stones >= 3) {
            if (stones % 3 == 0) {
                res = res || !judge(stones / 3, 1);
            } else if (stones % 3 == 1) {
                res = res || (!judge(stones / 3, 1) && !judge(stones / 3 + 1, 1));
                res = res || (!judge(stones / 3, 0) && !judge(stones / 3 + 1, 1));
            } else {
                res = res || (!judge(stones / 3 + 1, 1) && !judge(stones / 3, 1));
                res = res || (!judge(stones / 3 + 1, 0) && !judge(stones / 3, 1));
            }
        }
    } else {
        if (stones % 2 == 0) {
            res = res || (!judge(stones / 2, 1) && !judge(stones / 2, 0));
        } else {
            res = res || (!judge(stones / 2, 1) && !judge(stones / 2 + 1, 0));
            res = res || (!judge(stones / 2, 0) && !judge(stones / 2 + 1, 1));
        }

        if (stones >= 3) {
            if (stones % 3 == 0) {
                res = res || !judge(stones / 3, 0);
                res = res || (!judge(stones / 3, 0) && !judge(stones / 3, 1));
            } else if (stones % 3 == 1) {
                res = res || (!judge(stones / 3, 0) && !judge(stones / 3 + 1, 0));
                res = res || (!judge(stones / 3, 1) && !judge(stones / 3 + 1, 0));
            } else {
                res = res || (!judge(stones / 3 + 1, 0) && !judge(stones / 3, 0));
                res = res || (!judge(stones / 3 + 1, 1) && !judge(stones / 3, 0));
            }
        }
    }

    return table[stones][e_or_o] = res;
}

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

    memset(table, -1, sizeof(table));
    if (judge(n, 1)) {
        cout << "A" << endl;
    } else {
        cout << "B" << endl;
    }
    return 0;
}