#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, x, n) for(int i = x; i <= n; i++)
#define rep3(i, x, n) for(int i = x; i >= n; i--)
#define elif else if
#define sp(x) fixed << setprecision(x)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const ll MOD = 1000000007;
//const ll MOD = 998244353;
const int inf = (1<<30)-1;
const ll INF = (1LL<<60)-1;
const double pi = acos(-1.0);
const double EPS = 1e-10;
template<typename T> bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;};
template<typename T> bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;};

int memo[101];

int grundy(int n){
    if(memo[n] != -1) return memo[n];
    set<int> s;
    if(n >= 2){
        int tmp = 0;
        rep(i, 2) tmp ^= grundy((n+i)/2);
        s.insert(tmp);
    }
    if(n >= 3){
        int tmp = 0;
        rep(i, 3) tmp ^= grundy((n+i)/3);
        s.insert(tmp);
    }
    int ret = 0;
    while(s.count(ret)) ret++;
    return memo[n] = ret;
}

int main(){
    int N;
    cin >> N;
    fill(memo, memo+101, -1);
    cout << (grundy(N)? "A" : "B") << endl;
}