#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>
#include <queue>
#include <complex>

#define INF_MIN 100000000
#define INF 1145141919
#define INF_MAX 2147483647
#define LL_MAX 9223372036854775807
#define EPS 1e-10
#define PI acos(-1)
#define LL long long

using namespace std;

#define MAX_N 101

int N;
int grundy[MAX_N];

int main(){

  cin >> N;
  grundy[1] = 0;
  
  for(int i = 2; i <= N; i++){
    
    set<int> S;
    S.insert(grundy[i/2] ^ grundy[(i+1)/2]);
    if(i >= 3)
      S.insert(grundy[i/3] ^ grundy[(i+1)/3] ^ grundy[(i+2)/3]);

    for(int num = 0; ; num++){
      if(S.find(num) == S.end()){
	grundy[i] = num;
	break;
      }
    }

  }

  if(grundy[N] != 0)
    cout << "A" << endl;
  else
    cout << "B" << endl;

  return 0;

}