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

#define rep(i, n) for (int i=0; i<(int)n; i++)
using ll = long long int;

int main() {
  ll N;
  cin >> N;
  auto dfs = [&](auto dfs, ll x, string S) {
    if (x == N) {
      rep(i, (int)S.size())
	cout << S[i];
      cout << endl;
      return true;
    }
    if (x > N)
      return false;
    bool ret = false;
    ret = (dfs(dfs, x * 2 + 1, S + 'A')) || ret;
    ret = (dfs(dfs, x * 3 + 1, S + 'B')) || ret;
    return ret;
  };
  dfs(dfs, 1, "");
  return 0;
}