#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> VI;
typedef vector<VI> VVI;
#define REP(i, n)           for(int(i)=0;(i)<(n);++(i))
#define FOR(i, f, t)        for(int(i)=(f);(i)<(t);(++i))
#define RREP(i, n)          for(int(i)=(n)-1;(i)>=0;--(i))
const int MOD = int(1e9+7);

const int MAXN = 100;
int dp[MAXN+1];
int grundy(const int n){
    if(n == 1) return 0;
    if(dp[n] >= 0) return dp[n];

    // 状態遷移先
    set<int> s;
    int m1,m2,m3;
    m1 = n/2, m2 = n-m1;
    s.insert(grundy(m1)^grundy(m2));

    if(n >= 3){
        m1 = n/3, m2 = (n-m1)/2, m3 = n-m1-m2;
        s.insert(grundy(m1)^grundy(m2)^grundy(m3));
    }

    int g = 0;
    while(s.count(g)) g++;
    cerr<<"grundy["<<n<<"]="<<g<<" =>";
    for(auto it=s.begin(); it!=s.end(); ++it) cerr<<" "<<*it;
    cerr<<endl;
    return dp[n] = g;
}

int main(){
    memset(dp,-1,sizeof(dp));
    REP(i,MAXN) grundy(i+1);

    int N; cin >> N;
    cout << (grundy(N)?"A":"B") << endl;
}