#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const int inf = 1e9 + 9;
const ll mod = 1e9 + 7;
const double eps = 1e-8;
const double pi = acos(-1);

int n;
int grundy[110];

int calc_grundy(int k) {
    if (grundy[k] < 0) {
        set<int> s;
        switch(k%2) {
        case 0: s.insert(0); break;
        case 1: s.insert(calc_grundy(k/2)^calc_grundy(k/2+1)); break;
        }
        if (k >= 3) {
            switch(k%3) {
            case 0: s.insert(calc_grundy(k/3)); break;
            case 1: s.insert(calc_grundy(k/3+1)); break;
            case 2: s.insert(calc_grundy(k/3)); break;
            }
        }
        int res = 0;
        for (int v : s) {
            if (v != res) break;
            res++;
        }
        grundy[k] = res;
    }
    return grundy[k];
}

bool solve() {
    memset(grundy, -1, sizeof(grundy));
    grundy[1] = 0;
    return calc_grundy(n) != 0;
}

void input() {
    cin >> n;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    input();
    cout << (solve()?"A":"B") << endl;
}