#include <bits/stdc++.h>
using namespace std;

string adjust_taste(int N) {
    string steps = "";
    while (N != 1) {
        if (N % 2 == 0) {
            N /= 2;
            steps += 'A';
        } else {
            N = (N - 1) / 2;
            steps += 'B';
        }
    }
    reverse(steps.begin(), steps.end());
    return steps;
}

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

    string steps = adjust_taste(N);

    cout << steps << endl;

    return 0;
}