#include <bits/stdc++.h>

using namespace std;

namespace {

    typedef double real;
    typedef long long ll;

    template<class T> ostream& operator<<(ostream& os, const vector<T>& vs) {
        if (vs.empty()) return os << "[]";
        auto i = vs.begin();
        os << "[" << *i;
        for (++i; i != vs.end(); ++i) os << " " << *i;
        return os << "]";
    }
    template<class T> istream& operator>>(istream& is, vector<T>& vs) {
        for (auto it = vs.begin(); it != vs.end(); it++) is >> *it;
        return is;
    }

    int N;
    void input() {
        cin >> N;
    }

    int cache[101];
    bool win(int n) {
        if (cache[n] >= 0) return bool(cache[n]);

        int x, y, z;
        // div 2

        x = n / 2;
        y = n - x;
        if (win(x) ^ win(y) == 0) return cache[n] = true;

        // div 3
        x = n / 3;
        y = (n - x) / 2;
        z = n - x - y;
        if (win(x) ^ win(y) ^ win(z) == 0) return cache[n] = true;

        return cache[n] = false;
    }

    void solve() {
        memset(cache, -1, sizeof(cache));
        cache[1] = false;
        cache[2] = true;
        cache[3] = true;
        cout << (win(N) ? "A" : "B") << endl;
    }
}

int main() {
    input(); solve();
    return 0;
}