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

int g[110];

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

    g[2] = 1;
    for (int x = 3; x <= N; x++) {
        bool used[110] = {};
        if (x % 2 == 0) used[0] = true;
        else used[g[x / 2] ^ g[x / 2 + 1]] = true;

        if (x % 3 == 0) used[g[x / 3]] = true;
        else if (x % 3 == 1) used[g[x / 3 + 1]] = true;
        else used[g[x / 3]] = true;

        for (int n = 0; ; n++) {
            if (!used[n]) {
                g[x] = n;
                break;
            }
        }
    }

    /*
    for (int n = 2; n <= 10; n++) {
        cout << n << " ";
        if (g[n]) cout << "A" << endl;
        else cout << "B" << endl;
        cout << g[n] << endl;
    }
    */

    if (g[N]) cout << "A" << endl;
    else cout << "B" << endl;
    
    return 0;
}