#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

int main(){	
	
	int N;
	cin>>N;
	
	vector<int> dp(N+1,0);
	for(int i=2;i<=N;i++){
		set<int> S;
		if(i%2==0)S.insert(0);
		else S.insert(dp[i/2]^dp[(i+1)/2]);
		
		if(i>=3){
			if(i%3==0)S.insert(dp[i/3]);
			else if(i%3==1)S.insert(dp[(i+2)/3]);
			else S.insert(dp[i/3]);
		}
		rep(j,1000){
			if(!S.count(j)){
				dp[i] = j;
				break;
			}
		}
	}
	
	cout<<(dp.back()!=0?"A":"B")<<endl;
	
	return 0;
	
}