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

#define rep(i,x,y) for(int i=(x);i<(y);++i)
#define debug(x) #x << "=" << (x)

#ifdef DEBUG
#define _GLIBCXX_DEBUG
#define show(x) std::cerr << debug(x) << " (L:" << __LINE__ << ")" << std::endl
#else
#define show(x)
#endif

typedef long long int ll;
typedef pair<int,int> pii;
template<typename T> using vec=std::vector<T>;

const int inf=1<<30;
const long long int infll=1LL<<62;
const double eps=1e-9;
const int dx[]={1,0,-1,0},dy[]={0,1,0,-1};

template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec){
    os << "[";
    for (const auto &v : vec) {
    	os << v << ",";
    }
    os << "]";
    return os;
}

void solve(){
    vector<int> memo(101);
    vector<bool> done(101);
    memo[1]=0;
    done[1]=true;
    function<int(int)> grundy=[&](int x){
        auto &res=memo[x];
        if(done[x]) return res;
        done[x]=true;

        set<int> s;
        if(x%2==0) s.insert(0);
        else s.insert(grundy(x/2)^grundy(x/2+1));
        if(x>=3){
            if(x%3==0) s.insert(grundy(x/3));
            else if(x%3==1) s.insert(grundy(x/3+1));
            else s.insert(grundy(x/3));
        }

        while(s.count(res)!=0) ++res;
        return res;
    };

    int n;
    cin >> n;
    if(grundy(n)) cout << "A" << endl;
    else cout << "B" << endl;
}

int main(){
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    cout.setf(ios::fixed);
    cout.precision(10);
    solve();
    return 0;
}