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

typedef long long int ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pair<int, int> > vii;
#define rrep(i, m, n) for(int (i)=(m); (i)<(n);  (i)++)
#define erep(i, m, n) for(int (i)=(m); (i)<=(n); (i)++)
#define  rep(i, n)    for(int (i)=0; (i)<(n);  (i)++)
#define rrev(i, m, n) for(int (i)=(n)-1; (i)>=(m); (i)--)
#define erev(i, m, n) for(int (i)=(n); (i)>=(m); (i)--)
#define  rev(i, n)    for(int (i)=(n)-1; (i)>=0; (i)--)
#define vrep(i, c)    for(__typeof((c).begin())i=(c).begin(); i!=(c).end(); i++)
#define  ALL(v)       (v).begin(), (v).end()
#define mp            make_pair
#define pb            push_back
template<class T, class S> inline bool minup(T& m, S x){ return m>(T)x ? (m=(T)x, true) : false; }
template<class T, class S> inline bool maxup(T& m, S x){ return m<(T)x ? (m=(T)x, true) : false; }

const int    INF = 1000000000;
const ll     MOD = 1000000007LL;
const double EPS = 1E-12;

const int MAX_N = 100;
int n;
int dp[MAX_N + 1];

int grundy(int k)
{
  if(k == 1) return dp[1] = 0;
  if(k == 2) return dp[2] = 1;
  if(dp[k] >= 0) return dp[k];

  vi S;
  S.pb(grundy(k / 2) ^ grundy((k + 1) / 2));
  S.pb(grundy(k / 3) ^ grundy((k + 1) / 3) ^ grundy((k + 2) / 3));

  for(int i=0; ; i++) if(find(ALL(S), i) == S.end()) return dp[k] = i;
}

int main()
{
  cin >> n;

  erep(i, 1, n) dp[i] = -1;

  puts(grundy(n) ? "A" : "B");

  return 0;
}