#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int gmemo[101];
int grundy(int pos){
    int &r = gmemo[pos];
    if(r!=-1) return r;
    r = 0;
    if(pos <= 1)return r;

    set<int> st;
    if(pos % 2 == 0){
        st.insert(grundy(pos / 2) ^ grundy(pos / 2));
    } else{
        st.insert(grundy(pos / 2) ^ grundy(pos / 2 + 1));
    }
    if(pos >= 3){
        if(pos % 3 == 0){
            st.insert(grundy(pos / 3) ^ grundy(pos / 3) ^ grundy(pos / 3));
        } else if(pos % 3 == 1){
            st.insert(grundy(pos / 3) ^ grundy(pos / 3) ^ grundy(pos / 3 + 1));
        } else{
            st.insert(grundy(pos / 3) ^ (grundy(pos / 3 + 1) ^ grundy(pos / 3 + 1)));
        }
    }
    while(st.count(r))r++;
    return r;
}

int main(){
    MEM(gmemo, -1);
    int N;
    cin >> N;
    int ans = grundy(N);
    puts(ans ? "A" : "B");
}