#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    vector<int> dp(n + 1, -1);
    auto func = [&](auto&& self, int x) -> int {
        if(dp[x] != -1) return dp[x];
        if(x == 1)  return dp[x] = 0;
        set<int> G;
        if(x % 2 == 0){
            G.emplace(self(self, x / 2) ^ self(self, x / 2));
        }
        else{
            G.emplace(self(self, x / 2) ^ self(self, x / 2 + 1));
        }
        if(x >= 3){
            if(x % 3 == 0){
                G.emplace(self(self, x / 3) ^ self(self, x / 3) ^ self(self, x / 3));
            }
            else if(x % 3 == 1){
                G.emplace(self(self, x / 3) ^ self(self, x / 3) ^ self(self, x / 3 + 1));
            }
            else{
                G.emplace(self(self, x / 3) ^ self(self, x / 3 + 1) ^ self(self, x / 3 + 1));
            }
        }
        int res = 0;
        for(int i = 0; i <= 5; ++i){
            if(!G.count(i)){
                res = i;
                break;
            }
        }
        return dp[x] = res;
    };
    cout << (func(func, n) ? "A\n" : "B\n");

    return 0;
}