#include <bits/stdc++.h>
// #include <atcoder/all>
// using mint = atcoder::static_modint<998244353>;
// using mint = atcoder::static_modint<1000000007>;
using namespace std;
// using namespace atcoder;
using ld = long double;
using ll = long long;
#define mp(a,b) make_pair(a,b)
#define rep(i,s,n) for(int i=s; i<(int)n; i++)
const vector<int> dx{1,0,-1,0},dy{0,1,0,-1};

vector<int>memo(101,-1);
int solve(int x){
    if(memo[x]==-1){
        vector<bool> b(101,false);
        if(x%2==0)b[0]=true;
        else{
            b[solve(x/2)]=true;
            b[solve(x/2+1)]=true;
        }

        if(x%3==0)b[solve(x/3)]=true;
        else if(x%3==1)b[solve(x/3+1)]=true;
        else b[solve(x/3)]=true;

        memo[x]=0;
        while(b[memo[x]])memo[x]++;
    }
    return memo[x];
}

int main(){
    ll n;cin >> n;
    memo[0]=0;
    memo[1]=0;
    memo[2]=1;
    if(solve(n))cout << "A";
    else cout << "B";
}