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

int main() {
  long long N; cin >> N;
  string Ans;
  auto f = [&](auto f, long long X, string S) -> void {
    if (X == 1) {
      reverse(S.begin(), S.end());
      Ans = S;
      return;
    }
    if ((X - 1) % 2 == 0) f(f, (X - 1) / 2, S + 'A');
    if ((X - 1) % 3 == 0) f(f, (X - 1) / 3, S + 'B');
  };
  f(f, N, "");
  cout << Ans << endl;
}