#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <sstream>
#include <string>

#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define var auto
#define mod 1000000007
#define inf 2147483647
#define nil -1
typedef long long ll;

using namespace std;

inline int input(){
    int a;
    cin >> a;
    return a;
}

template <typename T>
inline void output(T a, int p) {
    if(p){
        cout << fixed << setprecision(p)  << a << "\n";
    }
    else{
        cout << a << "\n";
    }
}

// end of template

int main() {
    cin.tie(0);
    // source code
    int g[101];
    int N = input();
    
    g[0] = 0; // useless
    g[1] = 0;
    
    repd(i, 2, 101){
        int two = g[i / 2] ^ g[(i + 1) / 2];
        int three = g[i / 3] ^ g[(i + 1) / 3] ^ g[(i + 2) / 3];
        int ret = 0;
        while(1){
            if (two != ret && three != ret) {
                break;
            }
            ret++;
        }
        g[i] = ret;
    }
    
    output(g[N] ? "A" : "B", 0);
    
    
    
    return 0;
}