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

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

int main() {
	ll N;
	cin >> N;
	string ans = "";
	function<int(ll)> dfs = [&](ll x)
	{
		if(x == 1) return 0;
		ll nx = (x - 1) / 2;
		int m = (x - 1) % 2;
		if(m == 0 && nx > 0) {
			int ret = dfs(nx);
			if(ret == 0) {
				ans += "A";
				return 0;
			}
		}
		nx = (x - 1) / 3;
		m = (x - 1) % 3;
		if(m == 0 && nx > 0) {
			int ret = dfs(nx);
			if(ret == 0) {
				ans += "B";
				return 0;
			}
		}
		return -1;
	};
	dfs(N);
	cout << ans << endl;
}