#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[105];
    int gr(int n) {
        if (cache[n] >= 0) return cache[n];

        vector<int> st(101, 0);

        int x, y, z;
        // div 2
        x = n / 2;
        y = n - x;
        int a = gr(x) ^ gr(y);
        st[a] = true;

        // div 3
        x = n / 3;
        y = (n - x) / 2;
        z = n - x - y;
        int b = gr(x) ^ gr(y) ^ gr(z);
        st[b] = true;

        for (int i = 0; ; i++) {
            if (not st[i]) return cache[n] = i;
        }
    }

    void solve() {
        memset(cache, -1, sizeof(cache));
        cache[1] = 0;
        cache[2] = 1;
        cache[3] = 2;
        cout << (gr(N) == 0 ? "B" : "A") << endl;
    }
}

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