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

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<int> memo(n+1, -1);
    auto g = [&] (auto self, int a) -> int {
        if (a == 0) return memo[a] = 0;
        if (a == 1) return memo[a] = 0;
        if (memo[a] != -1) return memo[a];
        int res = 0;
        if (a & 1) {
            res ^= self(self, a/2);
            res ^= self(self, a/2 + 1);
        } else {
            res ^= self(self, a/2);
        }
        if (a % 3 == 0) {
            res ^= self(self, a/3);
        } else {
            res ^= self(self, a/3);
            res ^= self(self, a/3 + 1);
        }
        return -1;
    };
    cout << (g(g, n) == 0? "B" : "A") << "\n";
}