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

long long N;
vector<string> ans_all;

mt19937 ra(time(NULL));

void dfs(long long x, string S) {
  if(x == N) {
    ans_all.push_back(S);
  }else if(x < N) {
    if(ra() & 1) {
      dfs(2 * x + 1, S + 'A');
      dfs(3 * x + 1, S + 'B');
    }else {
      dfs(3 * x + 1, S + 'B');
      dfs(2 * x + 1, S + 'A');
    }
  }
}

int main() {
  cin >> N;
  dfs(1, "");
  assert(ans_all.size() == 1);
  cout << ans_all[0] << endl;
}